Quantum control devices and methods

Abstract

To provide a quantum control device that interacts with a quantum state through an electric field.SOLUTION: In a general aspect, a quantum control device includes a substrate having a substrate surface. An insulator layer is disposed over the substrate surface and defines a cavity. The insulator layer includes an insulator surface which defines an opening to the cavity. The quantum control device further includes a field-responsive layer over the insulator surface. The field-responsive layer includes a target region that resides over the opening to the cavity. The quantum control device further includes a projection extending from the substrate into the cavity and terminating at a tip. The projection is configured to generate an electric field interacting with a quantum state in the target region. The tip resides in the cavity and configured to concentrate the electric field generated by the projection.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 815,974, filed March 8, 2019, the disclosure of which is incorporated herein by reference. [Background technology]

[0002] The following description relates to quantum control devices and methods for operating quantum control devices.

[0003] Electric fields may be applied to materials to create useful devices. For example, electric fields may be applied to ferroelectric materials to create capacitors that can store electrical energy. In another example, electric fields may be applied to piezoelectric materials to create actuators that can displace objects. Currently, electric fields are primarily used in devices based on the classical properties of materials. These classical properties may result in properties of materials that are manifested on macroscopic scales of length (e.g., greater than 10 μm). However, the ability of electric fields to interact with the quantum properties of materials may result in new types of useful devices. [Brief description of the drawings]

[0004] [Figure 1A] 1 is a schematic diagram of an exemplary quantum control device having a substrate and a protrusion. [Figure 1B] 1B is a schematic diagram of the example quantum control device of FIG. 1A, in which the enclosed space is completely filled with a dielectric material. [Figure 1C] 1B is a schematic diagram of the example quantum control device of FIG. 1A, in which the field-responsive layer includes a target layer and an intermediate layer. [Figure 2A] FIG. 13 presents four contour plots showing the simulated effect of electric field on an exemplary 200 nm graphene flake with theoretical boundaries. [Figure 2B]FIG. 13 presents four contour plots showing the simulated effects of electric and 12 T magnetic fields on an exemplary 200 nm graphene flake with theoretical boundaries. [Figure 3A] FIG. 2 is a schematic perspective view of an exemplary quantum control device including a plurality of protrusions disposed on a substrate. [Figure 3B] 3B is a schematic cross-sectional view of the example quantum control device of FIG. 3A. [Figure 4A] 1 is a schematic top view of a plurality of protrusions extending from a substrate into corresponding cavities in an insulator layer to define a rectangular array. [Figure 4B] 1 is a schematic top view of a plurality of protrusions extending from a substrate into corresponding cavities in an insulator layer to define a hexagonal array. [Figure 4C] 1 is a schematic top view of a subset of a plurality of protrusions extending from a substrate into corresponding cavities in an insulator layer to define a rectangular array. [Figure 5A] 1 is a schematic cross-sectional view of an exemplary quantum control device having an array of diffraction patterns formed on a substrate. [Figure 5B] 5B is a schematic bottom view of the example quantum control device of FIG. 5A. [Figure 6A] 1 is a schematic cross-sectional view of an exemplary quantum control device having an array of lenses formed on a substrate. [Figure 6B] 6B is a schematic bottom view of the example quantum control device of FIG. 6A. [Figure 7A] 1 is a schematic cross-sectional view of an example quantum control device having a conductive layer that includes a plurality of vacancies. [Figure 7B] 7B is a schematic bottom view of the example quantum control device of FIG. 7A. [Figure 8] FIG. 3B is a schematic cross-sectional view of two instances of the example quantum control device of FIG. 3A, facing each other and sharing a field-responsive layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] In some aspects of the presently described subject matter, a quantum control device is presented that interacts with a quantum state using an electric field. In particular, the quantum control device may include a substrate having a substrate surface. An insulator layer is disposed over the substrate surface and defines a cavity. The insulator layer includes an insulator surface that defines an opening to the cavity. The quantum control device also includes a field-responsive layer over the insulator surface. The field-responsive layer includes a target region positioned over the opening to the cavity. The quantum control device further includes a protrusion extending from the substrate into the cavity and terminating in a tip. The protrusion is configured to generate an electric field that interacts with a quantum state of the target region. The tip is positioned within the cavity and configured to concentrate the electric field generated by the protrusion.

[0006] In some aspects of the presently described subject matter, the quantum control device may include a substrate and an insulator layer defining an array of cavities. A field-responsive layer is disposed on the insulator layer and includes an array of target regions each aligned with a corresponding cavity. The quantum control device may also include protrusions extending from the substrate into the corresponding cavities. The protrusions are configured to [1] produce an electric field that interacts with a quantum state of a target region proximate the protrusion and [2] controls quantum coupling between the quantum state of the target region and the quantum state of an adjacent target region. The array of protrusions may enable the quantum control device to correlate the quantum states of each target region, thereby establishing one or more collective quantum states.

[0007] 1A, a schematic cross-sectional view of an exemplary quantum control device 100 having a substrate 102 and a protrusion 104 extending therefrom is presented. As shown in FIG. 1A, the substrate 102 includes a substrate surface 106, which may be a planar surface. The substrate 102 may be formed of a semiconductor material, such as silicon, germanium, silicon-germanium alloy, and gallium arsenide. However, other materials (e.g., insulators or metallic materials) are possible. The protrusion 104 extends from the substrate surface 106 into a cavity 108 and may define a columnar structure. However, other shapes (e.g., pyramidal, hemispherical, wedge-shaped, etc.) are possible. The protrusion 104 may be part of the substrate 102 as shown in FIG. 1A, or alternatively may be a separate structure coupled to the substrate 102. The protrusion 104 may be formed of the same material as the substrate 102 or a different material than the substrate 102. For example, the protrusions 104 may be formed of a metallic material (e.g., Mo, W, Cu, etc.), a semiconductor material (e.g., Si, Ge, Si-Ge alloys, GaN, GaAs, etc.), a carbonaceous material (e.g., diamond, carbon nanotubes, carbon nanorods, etc.), or a ceramic material (e.g., hexagonal boron nitride, metal oxides, etc.). Other materials are possible.

[0008] The exemplary quantum control device 100 includes an insulator layer 110 disposed on a substrate surface 106 and defining a cavity 108. The insulator layer 110 includes an insulator surface 112 that defines an opening 114 to the cavity 108. The insulator surface 112 may be a planar surface and may even be parallel to the substrate surface 106. The insulator layer 110 may be in contact with the substrate surface 106 as shown in FIG. 1A or may alternatively be coupled to the substrate 102 via one or more intermediate layers. Such intermediate layers may improve coupling of the insulator layer 110 to the substrate 102.

[0009] In some implementations, the cavity 108 is disposed completely through the insulator layer 110. In these implementations, the cavity 108 may be defined by a longitudinal axis and a cross-sectional area. The longitudinal axis may be linear, curved, or some combination thereof. The cross-sectional area may be bounded by any type of perimeter (e.g., a circle, a hexagon, an ellipse, a parallelogram, etc.). The cross-sectional area may also remain constant along the longitudinal axis or vary with distance across the insulator layer 110. For example, the cavity 108 may be a cylindrical cavity defined by a linear longitudinal axis and a circular cross-sectional area of ​​constant radius. In another example, the cavity 108 may have a frusto-conical shape defined by a linear longitudinal axis and a cross-sectional area that decreases in size with distance from the insulator surface 112. Other shapes of the cavity 108 are possible.

[0010] In some implementations, the insulator layer 110 is 1×10 8 It is made of a material with an electrical resistivity of Ω·cm or more. Examples of such materials are aluminum oxide (e.g., Al2O3), silicon oxide (e.g., SiO2, SiO x , etc.), silicon nitride (e.g., Si3N4), silicon oxynitride (e.g., SiO x N y ), hafnium oxide (e.g., HfO2), titanium nitride (e.g., TiN), etc. In some implementations, the material has a 1×10 10 Electrical resistivity of 1×10 Ω cm or greater at room temperature. 12 Electrical resistivity of 1×10 Ω cm or greater at room temperature. 14 It has an electrical resistivity of Ω·cm or more.

[0011] The example quantum control device 100 also includes a field-responsive layer 116 disposed on the insulator surface 112 and including a target region 118. The target region 118 may be positioned over the opening 114 to the cavity 108 and centered over the opening 114 opposite the protrusion 104. However, other locations of the target region 118 are possible (e.g., off-center, offset from the protrusion 104, etc.). In some cases, the field-responsive layer 116 is a patterned layer and may be formed of two or more materials. In some cases, the field-responsive layer 116 includes multiple layers. The multiple layers may include a ferromagnetic layer, and an antiferromagnetic layer, a superconducting layer, or any combination thereof. Other types of layers are possible. Still further, the multiple layers may define a sandwich-like structure having one or more of a ferromagnetic layer, an antiferromagnetic layer, and a superconducting layer sandwiched between other layers (e.g., a ferromagnetic layer, an antiferromagnetic layer, a superconducting layer, etc.).

[0012] The field-responsive layer 116 may have one or more quantum states associated with the target region 118 that change in response to an electric field. Examples of the one or more quantum states include those based on electronic band structure, electron spin, nuclear spin, magnetic order, magnetic moment, ferroelectric order, ferroelectric moment, atomic order, optical transitions, phonon dispersion, one or more discrete energy levels, etc. Other types of quantum states are possible, including those based on superpositions of quantum states and entanglement of quantum states.

[0013] The target region 118 may include features of the atomic structure of the reactive layer 116 that allow one or more quantum states to appear in the target region 118, enhance the interaction between one or more quantum states and the electric field, or both. The atomic structure may be a two-dimensional atomic structure, a three-dimensional atomic structure, an amorphous atomic structure, or some combination thereof. For example, the field-responsive layer 116 may include a layer of graphene, which corresponds to a two-dimensional atomic structure. Other examples of two-dimensional atomic structures include a layer of hexagonal boron nitride (e.g., h-BN), a layer of molybdenum sulfide (e.g., MoS2), and a layer of tungsten sulfide (e.g., WS2). In another example, the field-responsive layer 116 may include three-dimensional islands formed of diamond, such as on an outer or inner surface of the field-responsive layer 116. The three-dimensional islands may be partially or entirely embedded within the field-responsive layer. In yet another example, the field-responsive layer 116 can include nanoparticles formed of a metallic glass (e.g., an amorphous alloy of gold, silver, iron, and boron). The metallic glass can have a magnetic moment.

[0014] In some implementations, the target region 118 comprises an inclusion in the atomic structure of the field-responsive layer 116. An inclusion may result from an atom (or a group of atoms) occupying an interstitial space in the atomic structure. In some implementations, the target region comprises a substitution in the atomic structure of the field-responsive layer. A substitution may result from a chemical or isotopic substitution of one or more atoms for other atoms in the atomic structure. In some implementations, the target region 118 comprises a vacancy in the atomic structure of the field-responsive layer 116.

[0015] In some implementations, the target region 118 comprises an atom or molecule on the surface of the field-reactive layer 116. The atom or molecule may comprise multiple atoms or molecules and thus may be an individual atom, a cluster of atoms, a chemical functional group, a nanoparticle, one or more molecules, a two-dimensional island of atoms or molecules, a layered heterostructure based on an ordered arrangement of atoms, a patterned coating layer of atoms, etc. The atom or molecule may be disposed on an outer surface of the field-reactive layer 116. The atom or molecule may also be disposed on an inner surface of the field-reactive layer 116. In some cases, atoms or molecules are disposed on both the outer and inner surfaces of the field-reactive layer 116.

[0016] The exemplary quantum control device 100 further includes a protrusion 104 terminating in a tip 120. In some variations, multiple instances of the protrusion 104 may extend from the substrate 102 into the cavity 108 (i.e., multiple protrusions 104). The protrusion 104 may have a height-to-width ratio in the range of 2:1 to 10,000:1. In some cases, the protrusion 104 may have a height-to-width ratio in the range of 20:1 to 200:1. The protrusion 104 is configured to generate an electric field that interacts with a quantum state in the target region 118. The tip 120 is positioned within the cavity 108 and is configured to concentrate the electric field generated by the protrusion 104. In some cases, the tip 120 may concentrate the electric field in the target region 118 by at least 1×10 5 In some cases, the tip 120 is configured to focus the electric field at the target region 118 to a magnitude of at least 1×10 9 In some cases, the tip 120 is configured to focus the electric field at the target region 118 to a magnitude of at least 1×10 10 In some cases, the tip 120 is configured to focus the electric field at the target region 118 to a magnitude of at least 1×10 11 In some cases, the tip 120 is configured to focus the electric field at the target region 118 to a magnitude of at least 1×10 12 It is designed to concentrate the radiation to a magnitude of V / m.

[0017] Focusing of the electric field can be aided by the shape of the tip 120 and the placement of the tip 120 relative to the target region 118. For example, the tip 120 may have a conical shape, the narrowing taper of which allows the electric field to emerge from a substantially narrowed surface. The tip 120 may also include a textured surface and / or nanoparticles that aid in focusing the electric field. The tip 120 may further include substructures, such as lattice couplers, that aid in focusing the electric field. In another example, the tip 120 may be positioned within the cavity 108 less than 100 nm from the target region 118. Such placement may be advantageous in preventing the target region 118 from being subjected to high electric fields (e.g., at least 1×10 5 In some cases, the tip 120 is positioned within the cavity 108 less than 20 nm from the target region 118. In some cases, the tip 120 is positioned within the cavity 108 less than 15 nm from the target region 118. In some cases, the tip 120 is positioned within the cavity 108 less than 10 nm from the target region 118. In some cases, the tip 120 is positioned within the cavity 108 less than 5 nm from the target region 118. In some cases, the tip 120 is positioned within the cavity 108 less than 1 nm from the target region 118.

[0018] In some implementations, the protrusions 104 are formed of a material that is resistant to electron emission under high electric fields (or strong applied voltages). For example, the protrusions 104 may be formed of a material having a work function of at least 4.0 eV. Examples of such materials include semiconductor materials (e.g., Si, Ge, and Si-Ge alloys), metallic materials (e.g., Mo, W, and Cu), ceramic materials (e.g., h-BN, WO x , and MoO x), and carbonaceous materials (e.g., diamond, carbon nanotubes, and carbon nanorods). In some cases, protrusions 104 are formed of a material having a work function of at least 4.2 eV. In some cases, protrusions 104 are formed of a material having a work function of at least 4.4 eV. In some cases, protrusions 104 are formed of a material having a work function of at least 4.6 eV. In some cases, protrusions 104 are formed of a material having a work function of at least 4.8 eV. In some cases, protrusions 104 are formed of a material having a work function of at least 5.0 eV.

[0019] When formed of a semiconductor material, the protrusion 104 may include a doping profile that defines a spatial distribution of p-type dopants, n-type dopants, or both within the protrusion 104. The spatial distribution may be simple (e.g., a uniform distribution) or complex (e.g., a distribution that establishes one or more pn junctions along the protrusion 104). In some cases, the protrusion 104 is formed of a conductive material. The conductive material may have an electrical resistivity of less than 100 Ω·cm at room temperature. For example, the conductive material may be a doped silicon material having a room temperature electrical resistivity in the range of 2 to 50 Ω·cm. In other cases, the conductive material may have a room temperature electrical resistivity of less than 1×10 -1 The protrusions 104 may have an electrical resistivity of less than Ω·cm. In some variations, the protrusions 104 are formed of a material that becomes conductive when activated (e.g., when a voltage is applied to the protrusions 104). When activated, the material transitions to an electrical resistivity of less than 100 Ω·cm. In some cases, the protrusions 104 may include a coated outer surface. For example, the protrusions 104 may be formed of a first material (e.g., Si) and coated with a second material (e.g., Pt) having a higher work function than the first material. In some variations, the second material may be a superconducting material.

[0020] In some implementations, the substrate 102, the insulator layer 110, and the field reactive layer 116 define an enclosed space 122 within the cavity 108 (see dotted line in FIG. 1A). The enclosed space 122 includes a first clearance volume 124 between the protrusion and the insulator layer. The first clearance volume 124 may include a volume between a side of the protrusion 104 and a sidewall of the cavity 108. In some cases, the enclosed space 122 may also include a second clearance volume 126 between the protrusion 104 and the field reactive layer 116. The second clearance volume 126 may include a volume between the tip 120 of the protrusion 104 and an inner surface of the field reactive layer 116. The enclosed space 122 is operable to electrically isolate the protrusion 104 from the insulator layer 110. The enclosed space 122 may also help the insulator layer 110 electrically isolate the protrusion 104 from other protrusions within the corresponding cavity of the insulator layer 110 (e.g., when the quantum control device is part of an array of quantum control devices).

[0021] The enclosed space 122 may contain a vacuum within any portion thereof, including the entirety of the enclosed space. In some cases, the enclosed space 122 may contain a vacuum within any portion thereof, including the entirety of the enclosed space. -5 In some cases, the enclosed space 122 contains a vacuum pressure of 10 Torr or less. -8Torr or less vacuum pressure. The enclosed space 122 may also be at least partially filled with a dielectric material. Such filling may divide the enclosed space 122 into one or more internal chambers or, alternatively, completely fill the enclosed space 122. FIG. 1B presents a schematic diagram of the example quantum control device 100 of FIG. 1A in which the enclosed space 122 is completely filled with a dielectric material. The dielectric material may be a material having a dielectric constant ranging from 1 to 10. In some cases, the dielectric material has a dielectric constant greater than 10. In some cases, the dielectric material has a dielectric constant greater than 100. The dielectric material may also have a dielectric strength greater than 0.05 V / nm, and in many variations, greater than 1 V / nm. Examples of such materials include silicon oxide (e.g., SiO2), silicon nitride (e.g., Si3N4), boron nitride (e.g., h-BN), and diamond. In some cases, the dielectric material may be formed of the same material as the insulator layer 110.

[0022] In some implementations, the insulator layer 110 includes an inner sidewall 134 surrounding the protrusion 104, defining at least a portion of the cavity 108. The inner sidewall 134 may contact the insulator surface 112 at an opening 114 to the cavity 108. In some cases, the inner sidewall 134 is displaced from the protrusion 104 to create a gap (see, e.g., FIGS. 1A-1C). The gap may contribute to the first clearance volume 124 of the protrusion 104. In some cases, the inner sidewall 134 may contact the protrusion 104 along at least a portion of a surface of the protrusion 104. Such contact may embed the protrusion 104 within the insulator layer 110.

[0023] In further implementations, the opening 114 is a first opening 114 of the cavity 108, and the insulator surface 112 is a first insulator surface 112 of the insulator layer 110. The insulator layer 110 includes a second insulator surface 136 that is bonded to the substrate surface 106 and opposite the first insulator surface 112. Such bonding may include direct contact between the second insulator surface 136 and the substrate surface 106, or alternatively, may occur through one or more intermediate layers. The one or more intermediate layers may improve bonding of the insulator layer 110 to the substrate 102. In some cases, the substrate surface 106, the first insulator surface 112, and the second insulator surface 136 are planar surfaces. In these embodiments, the inner sidewall 134 extends into the thickness of the insulator layer 110 and abuts the second insulator surface 106 at a second opening 138 of the cavity 108. The protrusion 104 extends from the substrate 102 through the second opening 138 of the cavity 108 and extends to a height from the substrate 102 that is less than the thickness of the insulator layer 110 .

[0024] The exemplary quantum control device 100 may include an addressing layer 128 underlying the substrate 102, including an electrical contact 130 opposite the base 132 of the protrusion 104. The addressing layer 128 may be in contact with the substrate 102 as shown in FIG. 1A, or may alternatively be coupled to the substrate 102 via one or more intermediate layers. Such intermediate layers may improve coupling of the addressing layer 128 to the substrate 102. The electrical contact 130 may be configured to deliver a voltage to the substrate 102. The electrical contact 130 may also be configured to receive an electrical signal from the substrate 102 that represents the quantum state of the target region 118. In this capacity, the electrical contact 130 may be used to characterize the quantum state of the target region 118.

[0025] In implementations having an addressing layer 128, the substrate 102 may be configured to transmit a voltage to the protrusions 104 to generate an electric field, and to transmit an electrical signal from the protrusions 104 to the electrical contacts 130. The voltage potential of the substrate 102 may be controlled independently from the voltage potential of the tips 120 of the protrusions 104. Such independent control may be aided by the addressing layer 128 and the electrical contacts 130.

[0026] In operation, the exemplary quantum control device 100 experiences a voltage potential between the substrate 102 (or electrical contacts 130, if present) and the field-responsive layer 116 (or a layer thereover). In particular, a voltage can be applied to the substrate 102 (or electrical contacts 130), which is then transmitted to the protrusions 104 to establish a voltage potential. The voltage may be applied continuously or via a voltage pulse. The voltage pulse may have a duration of 1 millisecond or less. In some cases, the duration is 1 picosecond or less. In some cases, the duration is 100 femtoseconds or less (e.g., 10-40 femtoseconds).

[0027] To establish the voltage potential, the voltage may be supplemented with a laser. For example, the laser may generate a coherent beam of electromagnetic radiation that is received by the target area 118, the protrusion 104 (or multiple thereof), or both. When received, an electric field component of the coherent beam of electromagnetic radiation may modify (e.g., increase) the voltage potential between the protrusion 104 (or multiple thereof) and the target area 118. The voltage potential may include a pulse having a duration. In some cases, the duration of the pulse is 1 picosecond or less. In some cases, the duration of the pulse is 100 femtoseconds or less (e.g., 10-40 femtoseconds).

[0028] In response, an electric field is generated that extends from tips 120 of projections 104 and penetrates target area 118. Tips 120 function in part to concentrate the electric field to a high magnitude, where target area 118 is at least 1×10 5 It can be subjected to electric fields of magnitude of 1×10 V / m. 9 V / m. Upon being subjected to an electric field, one or more quantum states of target region 118 may emerge or their characteristics (e.g., number, occupancy, spin, energy, size, spatial distribution, coupling to other quantum states, etc.) may be altered. In this manner, the voltage potential may enable manipulation of one or more quantum states of target region 118, and in some cases, may enable manipulation of the quantum state of field-responsive layer 116.

[0029] Control of the electric field, such as by changing the magnitude or frequency of a voltage or by applying a voltage pulse, may allow interaction with one or more quantum states. Such interaction may change the properties of the target region 118 (or the field-responsive layer 116) and allow for the storage and manipulation of information represented by one or more quantum states. Examples of such properties include optical properties (e.g., light transmission, light reflection, light emission, polarization, phase, etc.), magnetic properties (e.g., magnetic moment, magnetic order, inductance, etc.), thermal properties (e.g., specific heat, thermal conductivity, etc.), electrical properties (e.g., resistivity, capacitance, etc.), and combinations thereof (e.g., photoelectron effect, magnetocaloric effect, etc.). Other properties are possible, such quantum properties being based on the correlation of two or more quantum states.

[0030] In some implementations, control of the electric field may establish an electrostatic potential well within the target region 118 that may result in one or more quantum states, each having a plurality of discrete energy levels. The plurality of discrete energy levels may be manipulated by the electric field to induce the target region 118 to function as an artificial atom. In this capacity, the target region 118 may contain a discrete number of electrons that populate a corresponding discrete spectrum of energy levels. Thus, the target region 118 may behave similarly to an atom with an effective nuclear charge controlled by the electric field. Such behavior may be achieved, controlled, or enhanced by quantum systems on the surface of the target region 118 or alternatively embedded (e.g., as an intrusion) within the target region 118. The quantum systems may include individual atoms, clusters of atoms, chemical functional groups, nanoparticles, one or more molecules, two-dimensional islands of atoms or molecules, stacked heterostructures based on regular arrangements of atoms, patterned cladding layers of atoms, and the like. In some cases, the electric field can induce the target region 118 to behave as a Rydberg atom. In these cases, one or more of the electrons in the target region 118 can be excited to high energies to create an artificial atom with a high principal quantum number.

[0031] In some implementations, control of the electric field can be used to manipulate (e.g., control position, change order or configuration, alter quantum state, etc.) quantum systems on the surface of the target region 118. The quantum systems can include individual atoms, clusters of atoms, chemical functional groups, nanoparticles, one or more molecules, two-dimensional islands of atoms or molecules, stacked heterostructures based on regular arrangements of atoms, patterned coating layers of atoms, etc. The quantum systems can have multiple quantum states, each having multiple discrete energy levels. Furthermore, the target region 118 can include a discrete number of electrons that populate a corresponding discrete spectrum of energy levels associated with the quantum system. In these cases, one or more of the electrons of the target region 118 can be excited to high energies to create atoms (or artificial atoms) with high principal quantum numbers. In some cases, the quantum system includes a Rydberg atom (e.g., an ionized Cs atom), a molecule with Rydberg-like states (e.g., homopolar diatomic molecules such as H2, P2, Cl2, acetylene, etc.), or a material with Rydberg-like states on the surface of the target region 118.

[0032] In some implementations, the field-responsive layer 116 includes multiple layers, including a target layer 140 and an intermediate layer 142, as shown in FIG. 1C. The target layer 134 encompasses the target area 118, and the intermediate layer 142 is disposed between the insulator layer 110 and the target layer 140. The thickness 144 of the intermediate layer 142 is a portion of the distance 146 between the tip 120 of the protrusion 104 and the target area 118 of the field-responsive layer 116. The distance 146 can be less than 100 nm. In some cases, the distance 146 is less than 20 nm from the target area 118. In some cases, the distance 146 is less than 15 nm from the target area 118. In some cases, the distance 146 is less than 10 nm from the target area 118. In some cases, the distance 146 is less than 5 nm from the target area 118. In some cases, the distance 146 is less than 1 nm from the target area 118.

[0033] In some implementations, the insulator layer 110 includes a first insulator layer overlying the substrate surface 106 and a second insulator layer between the first insulator layer and the field-responsive layer 116. In some implementations, the example quantum control device 100 includes a second insulator layer overlying the field-responsive layer 116. The second insulator layer can include holes facing the opening 114 of the cavity 108. In further implementations, the example quantum control device 100 includes a conductive layer overlying the second insulator layer. Holes in the second insulator layer can propagate through the conductive layer.

[0034] The exemplary quantum control device 100 may utilize optical stimulation of the protrusions 104 to generate or assist in generating an electric field. In some implementations, the substrate surface 106 is a first substrate surface, and the substrate 102 includes a second substrate surface opposite the first substrate surface. The first substrate surface, the second substrate surface, and the insulator surface (or the first insulator surface) are planar surfaces. The substrate also includes light-collecting structures formed on the second substrate surface opposite the base 132 of the protrusions 104. The light-collecting structures are configured to guide light to the protrusions 104. Examples of light-collecting structures include diffraction patterns formed on the second substrate and lenses formed on the substrate surface. These structures may be defined by the second substrate surface, or alternatively, may be defined by separate structures coupled to the second substrate surface.

[0035] The exemplary quantum control device 100 may also utilize optical stimulation of the target region 118 to assist the protrusions 104 in generating an electric field. In some implementations, the target region 118 of the field-responsive layer 116 includes nanoparticles disposed thereon. The nanoparticles may be operable to enhance an electric field component associated with a light beam (e.g., laser light) impinging on the target region 118. The enhanced electric field component may increase the magnitude of the electric field generated by the protrusions 104. The nanoparticles may be disposed on an inner or outer surface of the field-responsive layer 116. In some cases, the target region 118 is embedded within the field-responsive layer 116 along with the nanoparticles. In these cases, the nanoparticles and the target region 118 may define an intrusion in the field-responsive layer 116.

[0036] In some implementations, the example quantum control device 100 includes a laser configured to direct a beam of light onto the target region 118. The beam of light may include one or more types of laser beams. The beam of light may also include one or more frequencies of electromagnetic radiation (e.g., frequencies of ultraviolet light). The laser may be operable to eject one or more electrons from the target region 118 by a process of photoemission. The example quantum control device 100 also includes an electron spectrometer configured to receive electrons emitted from the target region 118 in response to receiving the beam of light. The electron spectrometer may be capable of determining a characteristic of one or more quantum states of the target region 118 by measuring a characteristic of the electrons (e.g., the energy of the electrons). In further implementations, the example quantum control device 100 may include an optical spectrometer configured to determine a characteristic of one or more quantum states of the target region 118 by measuring a characteristic of the photons.

[0037] In some implementations, the example quantum control device 100 is configured to operate in a cryogenic environment. For example, the example quantum control device 100 may be disposed in a cryostat. The cryogenic environment may have any temperature below about 123 K (e.g., below 77 K, 4 K, 1 K, etc.). In some implementations, the example quantum control device 100 is configured to operate in a vacuum environment. For example, the example quantum control device 100 may be disposed in a sealable vacuum chamber coupled to one or more vacuum pumps (e.g., rotary vane pumps, turbomolecular pumps, cryogenic pumps, etc.). The vacuum environment may be a temperature below 10 K (e.g., below 10 K). -1 Less than 10 -3 Thor, 10 -6 Thor, 10 -9 In some implementations, the example quantum control device 100 may be configured to control the magnetic field (i.e.,

[0038]

number

[0039] FIG. 2A presents four contour plots 200, 202, 204, 206 showing the simulated effect of an electric field on an exemplary 200 nm graphene flake with theoretical boundaries. The four contour plots are generated from a computer simulation of the electric field on an exemplary 200 nm graphene flake using the Pybinding library. The density of states of an exemplary 200 nm graphene flake is shown responding to an increasing electric field from contour plot 200 to contour plot 206. The magnitude of the electric field is represented by β, which increases from 0.0 to 0.4, 0.8, and 1.2 as one moves from contour plot 200 to contour plot 202 to contour plot 204, and contour plot 206, respectively. The density of states is represented in FIG. 2A by the shades of gray underlying the contours of each contour plot. The grayscale legend on the right hand side of Figure 2A maps each shade of gray to a corresponding magnitude of the density of states. The density of states in the grayscale legend is 10 -3 From 10 -1 eV -1 nm -2 The range is as follows:

[0040] The abscissa of each contour plot indicates the distance in nanometers from the center of the exemplary 200 nm graphene flake (i.e., r=0 nm). The exemplary 200 nm graphene flake may define a field-responsive layer, such as field-responsive layer 116 described in connection with FIGS. 1A-1C. A portion of the exemplary 200 nm graphene flake at or immediately adjacent to the center may also define a target region, such as target region 118 described in connection with FIGS. 1A-1C. The ordinate of each contour plot indicates energy levels in electron volts (eV) that may be related to the energy of the density of states. The dotted line 208 indicates a band profile for electrons that respond to the presence of an electric field. For a non-zero electric field (i.e., β>0), the band profile may define an electrostatic potential well around the center of the 200 nm graphene flake (or its target region), as described below in connection with contour plots 200, 202, 204, 206.

[0041] As the contour plot 200 shows, the density of states at β=0 is constant as one travels a horizontal distance from r=−30 nm to r=30 nm. -3 eV -1 nm -2 A band spacing having a peak width of r = -30 nm to r = 30 nm extends on either side of the 0 eV energy level. In contour plot 200, there is no electric field (i.e., β = 0), and dotted line 208 is a horizontal line approximately aligned with the 0 eV energy level. However, the presence of an electric field (i.e., β > 0) can modify this band spacing profile to form an electrostatic potential well. The electric field can be generated by one or more sources. For example, a protrusion (or a tip thereof) can be positioned proximate to the center of the exemplary 200 nm graphene flake. A voltage applied to the protrusion (or a tip thereof) establishes a voltage potential on the exemplary 200 nm graphene flake. This voltage potential can generate an electric field from the protrusion (or a tip thereof) toward the center of the exemplary 200 nm graphene flake. Other examples of sources include interstitials in the atomic structure of the exemplary 200 nm graphene flake, substitutions in the atomic structure of the exemplary 200 nm graphene flake, voids in the atomic structure of the exemplary 200 nm graphene flake, and atoms or molecules on the surface of the exemplary 200 nm graphene flake.

[0042] At β=0.4, the electric field (or voltage) modifies the band spacing profile and induces the formation of an electrostatic potential well as shown by contour plot 202. The electric field also increases the density of states at approximately r=0 nm, which is concentrated at energy levels above 0 eV. The density of states at approximately r=0 nm corresponds to the local density of states. As shown in contour plot 204, increasing the electric field to β=0.8 widens the electrostatic potential well and increases its curvature. The magnitude of the local density of states continues to increase and extends to energy levels below 0 eV. As shown in contour plot 206, at β=1.2, the local density of states reaches a significant magnitude, especially at energy levels below 0 eV. It will be appreciated that the electric field (or voltage) can confine one or more electrons within a target region of the exemplary 200 nm graphene flake by inducing the formation of an electrostatic potential well and increasing the local density of states. Such localization of electrons can enable a target region to have a quantum state that is controllable by one or both of electric and magnetic fields.

[0043] For example, the presence of a magnetic field can split the local density of states into multiple discrete energy levels (or Landau levels) that can define one or more quantum states. One or more quantum states can be associated with a target region of a 200 nm graphene flake. In FIG. 2B, four contour plots 210, 212, 214, 216 are presented that show the simulated effect of an electric field and a 12 T magnetic field on an exemplary 200 nm graphene flake with theoretical boundaries. The four contour plots are generated from a computer simulation of an electric field and a 12 T magnetic field on an exemplary 200 nm graphene flake using the Pybinding library. The contour plots 210, 212, 214, 216 are similar to the contour plots 200, 202, 204, 206 of FIG. 2A, except that the exemplary 200 nm graphene flake is simulated in the additional presence of a 12 T magnetic field. For β=0, the density of states is still constant as one travels horizontal distance from r=-30 nm to r=30 nm. However, the presence of a 12 T magnetic field results in the appearance of two band spacings, where only one was present in the absence of a magnetic field (compare contour plot 200 in FIG. 2A). In particular, the first band spacing is below 0 eV and the second band spacing is above 0 eV. The first and second band spacings are approximately 10 -2 eV -1 nm -2 The dotted line 208 is horizontal along the energy level at about 0 eV and lies within this narrow band interval.

[0044] At β=0.4, the electric field (or voltage) modifies the profile of the first band spacing, the second band spacing, and the narrow band spacing, inducing the formation of an electrostatic potential well as shown in the contour plot 212. The electric field also increases the magnitude of the local density of states (i.e., at approximately r=0 nm), which is concentrated at energy levels beyond the second band spacing. Increasing the electric field to β=0.8 splits the narrow band spacing into two parts, one part in the first band spacing and one part in the second band spacing, as shown in the contour plot 214. Increasing the electric field also widens the electrostatic potential well and increases its curvature. The magnitude of the local density of states continues to increase, extending to energy levels below 0 eV. Furthermore, the local density of states splits into a number of discrete energy levels 218, which may correspond to Landau levels. The discrete energy levels 218 may define one or more quantum states. Further increasing the electric field to β=1.2 may cause further splitting of multiple discrete energy levels 218. However, as the contour plot 216 shows, increasing the electric field also increases the magnitude of the local density of states, especially for energy levels below 0 eV. Increasing the local density of states may enable one or more electrons to be increasingly confined to a target region of the exemplary 200 nm graphene flake.

[0045] As the contour plots 210, 212, 214, and 216 show, control of the electric field allows for localization of electrons within a target region of the exemplary 200 nm graphene flake. However, due to the presence of a 12 T magnetic field, such control also allows for the localized electrons to be dispersed across a number of discrete energy levels 218. By varying the magnitude of the electric field, which can manipulate the quantum state of the electrons and the number of discrete energy levels 218, respectively, the electrons, the number of discrete energy levels 218, or both can be manipulated. Such manipulation can allow for the emergence or modification of properties of the target region (or the exemplary 200 nm graphene flake). Such manipulation can also allow for the storage and manipulation of information represented by the quantum state. Although the contour plots 210, 212, 214, 216 present the simulation in the context of a constant magnetic field, the magnitude of the magnetic field may be varied to manipulate either or both of the electrons and the number of discrete energy levels 218.

[0046] 1A-1C, in some implementations, the example quantum control device 100 includes an optical waveguide associated with the target region 118. The optical waveguide may be defined by the insulator layer 110 (or a portion thereof), the field-responsive layer 116 (or a portion thereof), the cavity 108 (or a portion thereof), or any combination thereof. In some cases, the optical waveguide may include one or more sublayers of the insulator layer 110, one or more sublayers of the field-responsive layer 116, or both. The optical waveguide may be configured to propagate photons in the plane of one or both of the insulator layer 110 and the field-responsive layer 116. The optical waveguide may also be configured to propagate photons out of the plane of the insulator layer 110 or the field-responsive layer 116. For example, the optical waveguide may include a surface associated with the cavity 108 (eg, an end face, a sidewall surface, etc.) that enables reflection of photons along the longitudinal axis of the protrusion 104 (or protrusions).

[0047] The optical waveguide may have an active volume for propagating (or resonating) photons within it. These photons may be frequency shaped or pulsed to optimize the quality and purity of the desired discrete quantum states. The photons may have wavelengths corresponding to microwave, infrared, visible, or ultraviolet wavelengths. Other wavelengths are possible. In operation, photons within the active volume may couple to a quantum state of a target region 118 associated with the optical waveguide. The optical waveguide may then be used to select or control the quantum state of the target region 118. The optical waveguide may also be used to induce new quantum states of the target region 118. Coupling between photons and quantum states may modify the energy of the quantum state. Such coupling may also establish a quantum system whose behavior is governed by cavity quantum electrodynamics.

[0048] According to an illustrative example, a quantum control method may be used to operate the quantum control device 100 described in connection with FIGS. 1A-1C. The quantum control method includes generating an electric field from a protrusion on a substrate. The protrusion extends from a substrate surface of the substrate into a cavity defined by an insulator layer. Still further, the insulator layer is disposed on the substrate surface and includes an insulator surface defining an opening to the cavity. The quantum control method also includes receiving the electric field at a target region of the field-responsive layer. The field-responsive layer is disposed on the insulator layer, and the target region is positioned over the opening of the cavity. The quantum control method further includes controlling the electric field to interact with a quantum state of the target region of the field-responsive layer. In some cases, the quantum control method includes not transferring electrons from the protrusion to the target region of the field-responsive layer while generating the electric field. In some cases, the quantum control method includes transferring electrons from the protrusion to the target region of the field-responsive layer while generating the electric field.

[0049] In some implementations, generating an electric field at the protrusions includes focusing the electric field with tips of the protrusions. In these implementations, subjecting the electric field at the target area includes subjecting the focused electric field at the target area. The focused electric field is at least 1×10 5 In some cases, the focused electric field may have a magnitude of at least 1×10 9 In some cases, the focused electric field has a magnitude of at least 1×10 10 In some cases, the focused electric field has a magnitude of at least 1×10 11 In some cases, the focused electric field has a magnitude of at least 1×10 12 It has a magnitude of V / m.

[0050] In some implementations, generating an electric field from the protrusions includes applying a voltage to an electrical contact below the substrate opposite the base of the protrusions. Generating an electric field from the protrusions also includes transmitting a voltage through the substrate to the protrusions. In some implementations, the quantum control method includes transmitting an electrical signal from the protrusions to an electrical contact below the substrate opposite the base of the protrusions. The electrical signal can be used to characterize a quantum state of the target region.

[0051] In some implementations, the substrate surface is a first substrate surface, and the substrate includes a second substrate surface opposite the first substrate surface. In these implementations, generating an electric field from the protrusions includes receiving a light beam at a light-concentrating structure opposite a base of the protrusions. The light-concentrating structure is formed on the second substrate surface. Generating an electric field from the protrusions also includes guiding the light to the protrusions with the light-concentrating structure.

[0052] In some implementations, the quantum control method includes receiving a light beam at a target region of the field-responsive layer. For example, the light beam can be received by nanoparticles disposed on a metal surface of the field-responsive layer. The nanoparticles and the metal surface can define a penetration in the target region of the field-responsive layer. In another example, the light beam can eject one or more electrons from the target region by a process of photoemission. In a further implementation, the quantum control method includes receiving electrons emitted from the target region in response to the light beam in an electron spectrometer.

[0053] In some implementations, controlling the electric field to interact with the quantum state includes varying the magnitude of the electric field to modify the quantum state of the target region of the field-responsive layer.

[0054] In some implementations, the tip is positioned within the cavity less than 100 nm from the target area. In some implementations, the tip is positioned within the cavity less than 20 nm from the target area. In some implementations, the tip is positioned within the cavity less than 15 nm from the target area. In some implementations, the tip is positioned within the cavity less than 10 nm from the target area. In some implementations, the tip is positioned within the cavity less than 5 nm from the target area. In some implementations, the tip is positioned within the cavity less than 1 nm from the target area.

[0055] In some implementations, the protrusion is formed of a material having a work function of at least 4.0 eV. In some implementations, the protrusion is formed of a material having a work function of at least 4.2 eV. In some implementations, the protrusion is formed of a material having a work function of at least 4.4 eV. In some implementations, the protrusion is formed of a material having a work function of at least 4.6 eV. In some implementations, the protrusion is formed of a material having a work function of at least 4.8 eV. In some implementations, the protrusion is formed of a material having a work function of at least 5.0 eV. In some implementations, the protrusion has a height-to-width ratio in the range of 2:1 to 10000:1. In some implementations, the protrusion has a height-to-width ratio in the range of 20:1 to 200:1.

[0056] In some implementations, the target region comprises an intrusion in the atomic structure of the field-reactive layer. In some implementations, the target region comprises a substitution in the atomic structure of the field-reactive layer. In some implementations, the target region comprises a void in the atomic structure of the field-reactive layer. In some implementations, the target region comprises an atom or molecule on the surface of the field-reactive layer. The atom or molecule may comprise multiple atoms or molecules and thus may be an individual atom, a cluster of atoms, a chemical functional group, a nanoparticle, one or more molecules, a two-dimensional island of atoms or molecules, a layered heterostructure based on an ordered arrangement of atoms, a patterned coated layer of atoms, and the like. The atom or molecule may be disposed on an outer surface of the field-reactive layer. The atom or molecule may also be disposed on an inner surface of the field-reactive layer. In some cases, atoms or molecules are disposed on both the outer and inner surfaces of the field-reactive layer.

[0057]

[0023] Referring now to Figure 3A, a schematic perspective view of an example quantum control device 300 is provided that includes a plurality of protrusions 302 disposed on a substrate 304. In Figure 3A, certain features of the example quantum control device 300 have been omitted to allow other features to be viewed. In Figure 3B, a schematic cross-sectional view of the example quantum control device 300 of Figure 3A is provided. One or more of the plurality of protrusions in Figures 3A and 3B may be associated with individual instances of the example quantum control device 100 described in connection with Figures 1A-1C.

[0058] The example quantum control device 300 includes a substrate 304 and an insulator layer 306 that defines an array of cavities 308. The example quantum control device 300 also includes a field-responsive layer 310 disposed on the insulator surface 306 and including an array of target regions 312. In FIGS. 3A and 3B, the field-responsive layer 310 is depicted as having two layers. However, other numbers of layers are possible for the field-responsive layer 310 (e.g., one, five, etc.). Each target region 312 is aligned with a corresponding cavity 308. The protrusions 302 extend from the substrate 304 into the corresponding cavities 308 and are each configured to generate an electric field. The electric field interacts with the quantum state of the target region proximate the protrusion to control quantum coupling between the quantum state of the target region and the quantum state of an adjacent target region.

[0059] In many implementations, the plurality of protrusions 302 define a two-dimensional array. For example, as shown in FIG. 4A, the plurality of protrusions 400 may extend from a substrate 402 to define a rectangular array 404. One protrusion 400 is associated with each corresponding cavity 406 in an insulator layer 408. In another example, as shown in FIG. 4B, the plurality of protrusions 420 may extend from a substrate 422 to define a hexagonal array 424. One protrusion 420 is associated with each corresponding cavity 426 in an insulator layer 428.

[0060] The plurality of protrusions 302 may also define a two-dimensional array other than that defined by the array of cavities 308. In some implementations, at least one of the protrusions 302 includes a subset of protrusions 302 each producing a corresponding electric field that defines a portion of the electric field. For example, as shown in FIG. 4C, the plurality of protrusion subsets 440 may define a rectangular array 442. Each protrusion subset 440 is associated with a corresponding cavity 444 of the insulator layer 446 and has five protrusions 448 extending from the substrate 450 into the corresponding cavity 444. However, other numbers and arrangements of protrusions for each protrusion subset 440 are possible. Still further, the protrusion subsets 440 may define a two-dimensional array other than a rectangular array.

[0061] The multiple protrusions 302 may be regularly arranged to determine the distance between adjacent target regions 312. In some implementations, the distance may be 10 μm or less. The distance may be the same for all adjacent target regions 312. For example, the distance between adjacent target regions 312 may be 1000 nm or less for all adjacent target regions 312. The distance may also vary depending on the portion of the adjacent target regions 312. For example, the adjacent target regions 312 may include a first portion having a distance of 700 nm or less and a second portion having a distance of 300 nm or less. Other combinations of portions and distances are possible.

[0062] In some cases, the distance between adjacent target regions 312 is 1000 nm or less. In some cases, the distance between adjacent target regions 312 is 900 nm or less. In some cases, the distance between adjacent target regions 312 is 800 nm or less. In some cases, the distance between adjacent target regions 312 is 700 nm or less. In some cases, the distance between adjacent target regions 312 is 600 nm or less. In some cases, the distance between adjacent target regions 312 is 500 nm or less. In some cases, the distance between adjacent target regions 312 is 400 nm or less. In some cases, the distance between adjacent target regions 312 is 300 nm or less. In some cases, the distance between adjacent target regions 312 is 200 nm or less.

[0063] Each protrusion 302 may have a height to width ratio in the range of 2:1 to 10,000:1. In some cases, each protrusion 302 has a height to width ratio in the range of 20:1 to 200:1. Each protrusion 302 may also be formed of a material having a work function of at least 4.0 eV. In some cases, each protrusion 302 is formed of a material having a work function of at least 4.2 eV. In some cases, each protrusion 302 is formed of a material having a work function of at least 4.4 eV. In some cases, each protrusion 302 is formed of a material having a work function of at least 4.6 eV. In some cases, each protrusion 302 is formed of a material having a work function of at least 4.8 eV. In some cases, each protrusion 302 is formed of a material having a work function of at least 5.0 eV.

[0064] Each protrusion 302 may also terminate at a tip 314 that is positioned within the corresponding cavity 308. The tip 314 may terminate at a distance from the target area 312 proximate the protrusion 302. In many variations, the distance is the same for all tips 314 associated with the plurality of protrusions 302. In some cases, the tip 314 is positioned less than 100 nm from the proximate target area 312 in the corresponding cavity 308. In some cases, the tip 314 is positioned less than 20 nm from the proximate target area 312 in the corresponding cavity 308. In some cases, the tip 314 is positioned less than 15 nm from the proximate target area 312 in the corresponding cavity 308. In some cases, the tip 314 is positioned less than 10 nm from the proximate target area 312 in the corresponding cavity 308. In some cases, the tip 314 is positioned less than 5 nm from the proximal target region 312 within the corresponding cavity 308. In some cases, the tip 314 is positioned less than 1 nm from the proximal target region 312 within the corresponding cavity 308.

[0065] In some implementations, each protrusion 302 terminates in a tip that is configured to concentrate the electric field produced by the protrusion such that the tip concentrates the electric field at least 1×10 in a target area proximate the protrusion. 5 In some cases, the tip is configured to focus the electric field to a magnitude of at least 1×10 V / m in a target area proximate the protrusion. 9 In some cases, the tip is configured to focus the electric field to a magnitude of at least 1×10 V / m in a target area proximate the protrusion. 10 In some cases, the tip is configured to focus the electric field to a magnitude of at least 1×10 V / m in a target area proximate the protrusion. 11 In some cases, the tip is configured to focus the electric field to a magnitude of at least 1×10 V / m in a target area proximate the protrusion. 12 It is designed to concentrate the radiation to a magnitude of V / m.

[0066] In some implementations, the substrate 304, the insulator layer 306, and the field reactive layer 310 define an enclosed space within each cavity 308. The enclosed space includes a first clearance volume between the corresponding protrusion 302 and the insulator layer 306. In some variations, the enclosed space may also include a second clearance volume between the tip of the corresponding protrusion 302 and the field reactive layer 310. The enclosed space may include a first clearance volume between the tip of the corresponding protrusion 302 and the field reactive layer 310. -5 It is possible to contain a vacuum pressure of less than 10 Torr. In some cases, the enclosed space can be as low as 10 -8 The enclosed space contains a vacuum pressure of less than 1000 MPa (Torr). In some cases, the enclosed space is at least partially filled with a dielectric material.

[0067] In some implementations, at least one target region 312 includes an intrusion in the atomic structure of the field reactive layer 310. In some implementations, each target region 312 includes an intrusion in the atomic structure of the field reactive layer 310. The intrusions collectively define an array of intrusions aligned with the array of target regions 312. In some implementations, at least one target region 312 includes a substitution in the atomic structure of the field reactive layer 310. In some implementations, each target region 312 includes a substitution in the atomic structure of the field reactive layer 310. The substitutions collectively define an array of intrusions aligned with the array of target regions 312. In some implementations, at least one target region 312 includes a void in the atomic structure of the field reactive layer 310. In some implementations, each target region 312 includes a void in the atomic structure of the field reactive layer 310. Collectively, the voids define an array of voids that is aligned with the array of target areas 312 .

[0068] In some implementations, at least one target region 312 includes atoms or molecules on a surface of the field-responsive layer 310. The atoms or molecules may be disposed on an outer surface of the field-responsive layer 310. The atoms or molecules may also be disposed on an inner surface of the field-responsive layer 310. In some cases, atoms or molecules are disposed on both the outer and inner surfaces of the field-responsive layer 310. In some implementations, each target region 312 includes atoms or molecules on a surface of the field-responsive layer 310. The atoms or molecules collectively define an array of atoms or molecules aligned with the array of target regions 312. In FIGS. 2A and 2B, an example quantum control device 300 is depicted as having an array of atoms or molecules 316 on the outer surface of the field-responsive layer 310. In particular, each target region 312 includes atoms or molecules on the outer surface of the field-responsive layer 310. The atoms or molecules can include individual atoms, clusters of atoms, chemical functional groups, nanoparticles, one or more molecules, two-dimensional islands of atoms or molecules, layered heterostructures based on regular arrangements of atoms, patterned coating layers of atoms, and the like.

[0069] In some implementations, as shown in FIG. 3B, the exemplary quantum control device 300 includes an addressing layer 318 underlying the substrate 304, including electrical contacts 320 configured to receive a voltage signal. Each electrical contact 320 is aligned with a corresponding protrusion 302. In some variations, each electrical contact 320 is configured to deliver a corresponding voltage signal to the substrate 304, independent of the other electrical contacts. The substrate 304 is configured to transmit a corresponding voltage signal to the protrusion aligned with the electrical contact 320 to produce a corresponding electric field. In some variations, each electrical contact 320 is configured to receive an electrical signal from the substrate 304, independent of the other electrical contacts. The electrical signal can be used to characterize a quantum state of a target region proximate the protrusion aligned with the electrical contact. The substrate 304 is configured to transmit the electrical signal from the aligned protrusion to the electrical contact.

[0070] In some implementations, the protrusions 302 include a subset of the protrusions, and the exemplary quantum control device 300 includes an addressing layer 318 underlying the substrate 304 that includes a plurality of electrical contacts 320. Each electrical contact 302 is aligned with a corresponding subset of the protrusions and is configured to receive a voltage signal for the corresponding subset of the protrusions. In some variations, each electrical contact 320 is configured to deliver a corresponding voltage signal to the substrate 304, independent of the other electrical contacts. The substrate 304 is configured to transmit a corresponding voltage signal to the subset of the protrusions aligned with the electrical contact to produce a corresponding electric field. In some variations, each electrical contact 320 is configured to receive an electrical signal from the substrate 304, independent of the other electrical contacts. The electrical signal can be used to characterize a quantum state of a target region proximate the protrusion aligned with the electrical contact. The substrate 304 is configured to transmit the electrical signal from the aligned protrusions to the electrical contacts.

[0071] In operation, the example quantum control device 300 receives a voltage signal at one or more electrical contacts 320. The substrate 304 transmits the voltage signal to one or more corresponding protrusions 302 (or a subset of protrusions) to establish a voltage potential, which may be an electrostatic voltage potential. The voltage potential may exist between one or more corresponding protrusions 302 (or a subset of protrusions) and their corresponding target regions 312. The voltage signal may be applied continuously or via a voltage pulse. The voltage pulse may have a duration of 1 millisecond or less. In some cases, the duration is 1 picosecond or less. In some cases, the duration is 100 femtoseconds or less (e.g., 10-40 femtoseconds).

[0072] To establish a voltage potential, a voltage signal from one or more electrical contacts may be supplemented by a laser. For example, the laser may generate a coherent beam of electromagnetic radiation that is received by one or more target regions 312, one or more protrusions 302 (or a subset or protrusions), or both. When received, an electric field component of the coherent beam of electromagnetic radiation may modify (e.g., increase) the voltage potential between one or more corresponding protrusions 302 (or a subset thereof) and their corresponding target regions 312. The voltage potential may include a pulse having a duration. In some cases, the duration of the pulse is 1 picosecond or less. In some cases, the duration of the pulse is 100 femtoseconds or less (e.g., 10-40 femtoseconds).

[0073] In response, an electric field is generated by each of one or more corresponding protrusions 302 (or a subset of the protrusions), where the electric field extends from a corresponding tip 314 of the one or more corresponding protrusions 302 and penetrates the corresponding target area 312. The tip 314 in part helps to concentrate the electric field to a high magnitude, where the corresponding target area 312 is at least 1×10 5 In most cases, the magnitude is 1×10 9 When subjected to an electric field, the quantum states associated with each target region 312 may emerge or their properties (e.g., number, occupancy, spin, energy, size, spatial distribution, coupling to other quantum states, etc.) may be altered. For example, by varying the voltage signal received by one or more electrical contacts 320, the electric field can be varied to control the quantum coupling between the quantum states of adjacent target regions.

[0074] In operation, the electrical contacts 320 can also receive from the corresponding protrusions 302 electrical signals used to characterize one or more quantum states of each target region 312 proximate the corresponding protrusion 302. The electrical signals are transmitted from the corresponding protrusions 302 through the substrate 304. The addressing layer 318 is configured such that the electrical contacts 320 can receive electrical signals from one target region 312 independently from the other target regions 312. Similarly, the electrical contacts can also be voltaged such that an electric field for one target region 312 is generated (or changed) independently from the other target regions 312. Such a configuration of the addressing layer 318 enables the example quantum control device 300 to manipulate the quantum states of any combination of target regions 318 and to control quantum coupling between any combination of target regions 318.

[0075] In some implementations, the quantum state associated with each target region 312 is a discrete localized quantum state. In these implementations, the tips 314 of the protrusions 302 may be positioned close enough together that the discrete localized quantum states overlap. The degree of overlap can be further altered by varying one or more of the electric fields generated by the protrusions 302 (or a subset of the protrusions). Such overlap can induce a new collective quantum state that is maintained by the array of target regions 312 in the field-responsive layer. This collective quantum state may itself have one or more discrete states, and in some cases may have a band structure. The electric fields generated by the protrusions 302 (or a subset of the protrusions) may include electrostatic voltage potentials between the tips 314 and their corresponding target regions 312, and can be used to control and modify properties of these collective quantum states.

[0076] In some implementations, the example quantum control device 300 includes an optical waveguide associated with at least one target region 312 of the array of target regions 312. The optical waveguide may be defined by the insulator layer 306 (or a portion thereof), the field-responsive layer 310 (or a portion thereof), one or more cavities 308 (or a portion thereof), or any combination thereof. In some cases, the optical waveguide may include one or more sublayers of the insulator layer 306, one or more sublayers of the field-responsive layer 310, or both. The optical waveguide may be configured to propagate photons in the plane of one or both of the insulator layer 306 and the field-responsive layer 310. The optical waveguide may also be configured to propagate photons out of the plane of the insulator layer 306 or the field-responsive layer 310. For example, the optical waveguide may include surfaces associated with the cavity 308 (eg, end faces, sidewall surfaces, etc.) that enable reflection of photons along the longitudinal axis of the protrusions 302 (or a subset of the protrusions).

[0077] The optical waveguide may have an active volume for propagating (or resonating) photons within. These photons may be frequency shaped or pulsed to optimize the quality and purity of the desired discrete quantum states. The photons may have wavelengths corresponding to microwave, infrared, visible, or ultraviolet wavelengths. Other wavelengths are possible. In operation, photons within the active volume may couple to a quantum state of at least one target region 312 associated with the optical waveguide. The optical waveguide may then be used to select or control the quantum state of at least one target region 312. A quantum state may be associated with a single target region. If multiple target regions 312 are associated with the optical waveguide, a quantum state may be associated with more than one target region. The optical waveguide may also be used to induce a new quantum state of at least one target region 312. A new quantum state may be associated with a single target region. When multiple target regions 312 are associated with an optical waveguide, a new quantum state can be associated with more than one target region. Coupling between a photon and a quantum state can modify the energy of the quantum state. Such coupling can also establish a quantum system whose behavior is governed by cavity quantum electrodynamics.

[0078] An example quantum control device 300 may include multiple such quantum systems. The addressing layer 318 may allow the quantum systems to be manipulated individually or may allow the quantum systems to be manipulated in subgroups (e.g., adjacent groups). In implementations having multiple quantum systems, the corresponding optical waveguides may function as complex photonic waveguides that operate to interact with an array of target regions 312 throughout the quantum control device 300.

[0079] In some implementations, the example quantum control device 300 includes a laser system configured to direct a laser signal to the array of target regions 312. The laser may be operable to eject one or more electrons from one or more target regions 312 by a process of photoemission. The example quantum control device 300 also includes an electron spectrometer configured to receive electrons emitted from the array of target regions 312 in response to the laser system. The electron spectrometer may be capable of determining characteristics of one or more quantum states associated therewith by measuring properties of corresponding electrons emitted from each target region 312 (e.g., the energy of the corresponding electrons). In further implementations, the example quantum control device 300 may include an optical spectrometer configured to determine characteristics of one or more quantum states associated with each target region 312 by measuring properties of photons.

[0080] The example quantum control device 300 may utilize optical stimulation of a plurality of protrusions 302 to generate or assist in generating a corresponding electric field. In some implementations, the example quantum control device 300 includes an array of light-collecting structures below the substrate, each aligned opposite a corresponding cavity 308 and configured to guide light to the protrusion associated with the corresponding cavity 308. The light-collecting structures may include diffraction patterns, lenses, or mirrors. Other light-collecting structures are possible.

[0081] For example, FIG. 5A presents a schematic cross-sectional view of an exemplary quantum control device 500 having an array of diffraction patterns 502 formed on a substrate 504. FIG. 5B presents a schematic bottom view of the exemplary quantum control device 500 of FIG. 5A. The array of diffraction patterns 502 is aligned with an array of protrusions 506 extending from the substrate 504 into a corresponding array of cavities 508 in an insulating layer 510. In another example, FIG. 6A presents a schematic cross-sectional view of an exemplary quantum control device 600 having an array of lenses 602 formed on the substrate 604. FIG. 6B presents a schematic bottom view of the exemplary quantum control device 600 of FIG. 6A. The lenses may be part of the substrate 604 or may alternatively be bonded to the substrate 604 (e.g., fabricated by a microelectronics manufacturing process on the substrate 604). The array of lenses 602 is aligned with an array of protrusions 606 that extend from the substrate 604 into a corresponding array of cavities 608 in an insulating layer 610 .

[0082] The example quantum control device 300 may also use plasmonic action by optical stimulation to induce the plurality of protrusions 302 to generate or assist in generating a corresponding electric field. In some implementations, the example quantum control device 300 includes a conductive layer with vacancies arranged along a periodic lattice. The periodic lattice has a first portion occupied by vacancies and a second portion not occupied by vacancies. The second portion is aligned to be opposite the array of cavities 308, and in some variations, the second portion is aligned to be opposite a subset of the cavities in the array of cavities 308. The conductive layer may be below the substrate 304 or alternatively above the field-responsive layer 310. In some variations, there may be a conductive layer in the first case below the substrate 304 and a conductive layer in the second case below and over the field-responsive layer 310.

[0083] FIG. 7A provides a schematic cross-sectional view of an example quantum control device 700 having a conductive layer 700 including a plurality of vacancies 704. FIG. 7B provides a schematic bottom view of the example quantum control device 700 of FIG. 7A. A conductive layer 702 is disposed below a substrate 706 of the example quantum control device 700. The plurality of vacancies 704 are arranged on a periodic lattice having a first portion 706 where the vacancies are present and a second portion 708 where the vacancies are not present. The second portion 708 is aligned with an array of protrusions 710 that extend from the substrate 706 into an array of corresponding cavities 712 in an insulating layer 714. In operation, light is received by the conductive layer 702, inducing the transfer of charge to the second portion 708 via plasmonic action. The concentration of charge at the second locations 708 creates a high electric field that propagates through the substrate 706 and the corresponding protrusions 710 and then emerges from the tips of the corresponding protrusions 710. The high electric field may be in addition to the electric field generated by the plurality of protrusions 710 (e.g., in response to an applied voltage).

[0084] In some implementations, the example quantum control device 300 includes a plurality of trenches formed in the substrate 304 and positioned to isolate individual protrusions 302 extending from the substrate 304. Such isolation may be electrical isolation. In some implementations, a plurality of trenches are formed in the substrate 304 and positioned to isolate subsets of the protrusions 302 extending from the substrate 304. Such isolation may be electrical isolation. Each subset of protrusions 302 is associated with a single cavity 308.

[0085] The quantum control devices described herein may be configured such that each target region receives an electric field from two opposing protrusions. Such a configuration may improve the magnitude of the electric field experienced by each target region and may also improve the uniformity of the electric field (e.g., in-plane) within each target region. Figure 8 provides a schematic diagram of two instances 800, 802 of the example quantum control device of Figure 3A, which face each other and share a field-responsive layer 804. Opposing pairs of protrusions 806, 808 are aligned to generate corresponding electric fields that are each received by a shared target region 810.

[0086] In some implementations, the example quantum control device 300 is configured to operate in a cryogenic environment. For example, the example quantum control device 300 may be disposed in a cryostat. The cryogenic environment may have any temperature below about 123 K (e.g., below 77 K, 4 K, 1 K, etc.). In some implementations, the example quantum control device 300 is configured to operate in a vacuum environment. For example, the example quantum control device 300 may be disposed in a sealable vacuum chamber coupled to one or more vacuum pumps (e.g., rotary vane pumps, turbomolecular pumps, cryogenic pumps, etc.). The vacuum environment may be within a range of about 100 K (e.g., 100 K). -1 Less than 10 -3 Thor, 10 -6 Thor, 10 -9 In some implementations, the example quantum control device 300 may be configured to control the magnetic field (i.e.,

[0087]

number

[0088] A quantum control method may be used to operate the quantum control device 300 described in connection with Figures 3A-8. The quantum control method includes generating one or more electric fields from an array of protrusions on a substrate. Each electric field is generated by one or more protrusions extending from the substrate into a corresponding cavity in an insulator layer. The corresponding cavity is part of an array of cavities defined by an insulator layer, which is disposed above the substrate and below the field-responsive layer.

[0089] The quantum control method also includes subjecting one or more electric fields to corresponding target regions in the field-responsive layer, the corresponding target regions being part of an array of target regions in the field-responsive layer, each target region having a quantum state and aligned with a corresponding cavity in the array of cavities, and the method further includes controlling the one or more electric fields to cause a first quantum state of a first target region to interact with a second quantum state of at least a second target region.

[0090] In some implementations, generating the one or more electric fields includes focusing the one or more electric fields with corresponding tips of one or more protrusions associated with each electric field. In these implementations, subjecting the one or more electric fields at the corresponding target regions includes subjecting the one or more electric fields at the corresponding target regions after their focusing. Each of the one or more electric fields after focusing has a magnitude of at least 1×10 5 In some cases, the electric field or fields after focusing may each have a magnitude of at least 1×10 9 In some cases, the electric field or fields after focusing may each have a magnitude of at least 1×10 10 In some cases, the electric field or fields after focusing may each have a magnitude of at least 1×10 11 In some cases, the electric field or fields after focusing may each have a magnitude of at least 1×10 12 It may have a magnitude of V / m.

[0091] In some implementations, subjecting the one or more electric fields includes establishing discrete energy levels of a quantum state for at least one of the corresponding target regions. In some cases, all of the corresponding target regions have a quantum state having discrete energy levels. In some cases, the discrete energy levels include electronic energy levels. In some cases, the discrete energy levels include photon energy levels.

[0092] In some implementations, controlling the one or more electric fields includes modifying quantum coupling between a first quantum state of a first target region and a second quantum state of a second target region. In some implementations, the first target region is adjacent to the second target region. In some implementations, a distance between the adjacent target regions is 700 nm or less.

[0093] In some implementations, each protrusion of the array of protrusions terminates at a tip located less than 100 nm from the target area associated with the cavity in the cavity. In some implementations, each protrusion of the array of protrusions terminates at a tip located less than 20 nm from the target area associated with the cavity in the cavity. In some implementations, each protrusion of the array of protrusions terminates at a tip located less than 15 nm from the target area associated with the cavity in the cavity. In some implementations, each protrusion of the array of protrusions terminates at a tip located less than 10 nm from the target area associated with the cavity in the cavity. In some implementations, each protrusion of the array of protrusions terminates at a tip located less than 5 nm from the target area associated with the cavity in the cavity. In some implementations, each protrusion of the array of protrusions terminates at a tip located less than 1 nm from the target area associated with the cavity in the cavity.

[0094] In some implementations, each protrusion in the array of protrusions is formed of a material having a work function of at least 4.0 eV. In some implementations, each protrusion in the array of protrusions is formed of a material having a work function of at least 4.2 eV. In some implementations, each protrusion in the array of protrusions is formed of a material having a work function of at least 4.4 eV. In some implementations, each protrusion in the array of protrusions is formed of a material having a work function of at least 4.6 eV. In some implementations, each protrusion in the array of protrusions is formed of a material having a work function of at least 4.8 eV. In some implementations, each protrusion in the array of protrusions is formed of a material having a work function of at least 5.0 eV. In some implementations, each protrusion in the array of protrusions has a height-to-width ratio in the range of 2:1 to 10000:1. In some implementations, each protrusion in the array of protrusions has a height-to-width ratio in the range of 20:1 to 200:1.

[0095] In some implementations, at least one target region includes an intrusion in the atomic structure of the field-responsive layer. In some implementations, each target region includes an intrusion in the atomic structure of the field-responsive layer. In these implementations, the intrusions collectively define an array of intrusions aligned with the array of target regions. In some implementations, at least one target region includes a substitution in the atomic structure of the field-responsive layer. In some implementations, each target region includes a substitution in the atomic structure of the field-responsive layer. In these implementations, the substitutions collectively define an array of substitutions aligned with the array of target regions. In some implementations, at least one target region comprises a void in the atomic structure of the field-responsive layer. In some implementations, each target region comprises a void in the atomic structure of the field-responsive layer. In these implementations, the voids collectively define an array of voids aligned with the array of target regions.

[0096] In some implementations, at least one target region comprises atoms or molecules on a surface of the field-reactive layer. The atoms or molecules may be disposed on an outer surface of the field-reactive layer. The atoms or molecules may also be disposed on an inner surface of the field-reactive layer. In some cases, atoms or molecules are disposed on both the outer and inner surfaces of the field-reactive layer. In some implementations, each target region comprises atoms or molecules on a surface of the field-reactive layer. In these implementations, the atoms or molecules collectively define an array of atoms or molecules aligned with the array of target regions.

[0097] The quantum control device can also be described by the following example: Example 1. A substrate having a substrate surface; an insulator layer overlying the substrate surface and defining a cavity, the insulator layer having an insulator surface defining an opening to the cavity; a field-reactive layer overlying the insulator surface and including a target area positioned over an opening to the cavity; a protrusion extending from the substrate into the cavity and terminating at a tip, the protrusion configured to generate an electric field that interacts with a quantum state of the target region, the tip being positioned within the cavity and configured to concentrate the electric field generated by the protrusion; A quantum control device comprising: Example 2. The quantum control device of example 1, wherein the tip is positioned within the cavity less than 100 nm from the target region. Example 3. The quantum control device of example 1, wherein the tip is positioned within the cavity less than 20 nm from the target region. Example 4. The quantum control device of example 1 or example 2 or 3, wherein the protrusion is formed of a material having a work function of at least 4.0 eV. Example 5. A quantum control device according to any of Examples 1 or 2-4, wherein the protrusions have a height to width ratio in the range of 2:1 to 10000:1. Example 6. The tip of the protrusion is designed to generate an electric field of at least 1×10 5 The quantum control device of any one of Example 1 or Examples 2-5, configured to focus up to a magnitude of V / m. Example 7. The tip of the protrusion is designed to generate an electric field of at least 1×10 9 The quantum control device of any one of Example 1 or Examples 2-5, configured to focus up to a magnitude of V / m. Example 8. A quantum control device as described in Example 1 or any of Examples 2-7, wherein the substrate, the insulator layer, and the field-responsive layer define an enclosed space within the cavity, the enclosed space comprising a first clearance volume between the protrusion and the insulator layer. Example 9. The quantum control device of example 8, wherein the enclosed space comprises a second clearance volume between the protrusion and the field-responsive layer. Example 10. Enclosed space is 10 -5 10. The quantum control device of example 8 or 9, confined to a vacuum pressure of 0.1 MPa or less. Example 11. The quantum control device of example 8 or example 9 or 10, wherein the enclosed space is at least partially filled with a dielectric material. Example 12. A quantum control device according to any one of Example 1 or Examples 2 to 11, wherein the substrate surface and the insulator surface are planar surfaces. Example 13. A quantum control device according to any one of Example 1 or Examples 2 to 12, wherein the tip of the protrusion has a conical shape. Example 14. A quantum control device according to any one of Example 1 or Examples 2-13, wherein the tips of the protrusions have a textured surface. Example 15. A quantum control device according to any one of Example 1 or Examples 2-14, wherein the tips of the protrusions are provided with nanoparticles. Example 16. A quantum control device according to any one of Example 1 or Examples 2-15, wherein the tips of the protrusions have a coated outer surface. Example 17. The quantum control device of any of Example 1 or Examples 2-16, wherein the target region comprises an intrusion in the atomic structure of the field-responsive layer. Example 18. The quantum control device of any of Examples 1 or 2-17, wherein the target region comprises a substitution in the atomic structure of the field-responsive layer. Example 19. The quantum control device of any of Example 1 or Examples 2-18, wherein the target region comprises a void in the atomic structure of the field-responsive layer. Example 20. The quantum control device of any of Examples 1 or 2-19, wherein the target region comprises an atom or molecule on the surface of the field-responsive layer. Example 21. The quantum control device of example 20, wherein the atoms or molecules are disposed on an outer surface of the field-responsive layer. Example 22. The quantum control device of example 20, wherein the atoms or molecules are disposed on an inner surface of the field-responsive layer. Example 23. The quantum control device of any one of Example 1 or Examples 2-22, wherein the field-responsive layer is a patterned layer. Example 24. The quantum control device of example 23, wherein the patterned layer is formed of two or more materials. Example 25. The quantum control device of any of Examples 1 or 2-22, wherein the field-responsive layer comprises a plurality of layers. Example 26. The quantum control device of example 25, wherein the plurality of layers includes a patterned layer. Example 27. Multiple layers a target layer including a target region; an intermediate layer disposed between the insulator layer and the target layer; 27. The quantum control device of Example 25 or 26, wherein the thickness of the intermediate layer is a portion of the distance between the tip of the protrusion and the target area of ​​the field-responsive layer. Example 28. The quantum control device of example 27, wherein the distance is less than 100 nm. Example 29. The quantum control device of example 27, wherein the distance is less than 20 nm. Example 30. The quantum control device of any of Examples 1 or 2-29, wherein the field-responsive layer comprises a layer of graphene. Example 31. The quantum control device of any of Examples 1 or 2-30, comprising a plurality of protrusions, each of which extends from the substrate into the cavity and terminates in a tip. Example 32. The quantum control device of any of Examples 1 or 2-31, wherein the substrate and the protrusion (or protrusions) are formed of different materials. Example 33. The quantum control device of any of Examples 1 or 2-31, wherein the substrate and the protrusion (or protrusions) are part of the substrate. Example 34. The insulating layer is a first insulator layer overlying a surface of the substrate; The quantum control device of any one of Example 1 or Examples 2-33, comprising a second insulator layer between the first insulator layer and the field-responsive layer. Example 35. The quantum control device of any of Examples 1 or 2-34, comprising a second insulator layer overlying the field-responsive layer. Example 36. The quantum control device of example 35, wherein the second insulator layer has a hole facing the opening of the cavity. Example 37. The quantum control device of example 35 or 36, comprising a conductive layer overlying the second insulator layer. Example 38. A quantum control device according to any of Examples 1 or 2-37, comprising an addressing layer underlying the substrate, the addressing layer comprising electrical contacts opposite the base of the protrusions. Example 39. The quantum control device of example 38, wherein the electrical contacts are configured to deliver a voltage to the substrate, and the substrate is configured to transmit a voltage to the protrusions to produce an electric field. Example 40. A quantum control device as described in Example 38 or 39, wherein the electrical contact is configured to receive an electrical signal from the substrate, the electrical signal characterizing a quantum state of the target region, and the substrate is configured to transmit the electrical signal from the protrusion to the electrical contact. Example 41. The quantum control device of any of Examples 1 or 2-40, wherein the insulator layer comprises an inner sidewall surrounding a protrusion that defines at least a portion of the cavity. Example 42. The quantum control device of example 41, wherein the inner sidewall abuts the insulator surface at the opening to the cavity. Example 43. The opening is a first opening of a cavity and the insulator surface is a first insulator surface of an insulator layer; the insulator layer is bonded to the substrate surface and has a second insulator surface opposite the first insulator surface; an inner sidewall extends through the thickness of the insulator layer and abuts the second insulator surface at the second opening of the cavity; The projection extends from the substrate through a second opening of the cavity; the protrusion extends from the substrate to a height that is less than the thickness of the insulator layer; The quantum control device of example 41 or example 42. Example 44. The quantum control device of example 43, wherein the substrate surface, the first insulator surface, and the second insulator surface are planar surfaces. Example 45. The substrate surface is a first substrate surface, the substrate comprising: a second substrate surface opposite the first substrate surface; and a light concentrating structure formed on a second substrate surface opposite the base of the protrusion, the light concentrating structure being configured to guide light to the protrusion. The quantum control device according to any one of Example 1 or Examples 2 to 44. Example 46. The quantum control device of example 45, wherein the light-concentrating structure is a diffraction pattern formed on the surface of the second substrate. Example 47. The quantum control device of example 45, wherein the light-concentrating structure is a lens formed on the second substrate surface. Example 48. The quantum control device of example 45, wherein the first substrate surface, the second substrate surface, and the insulator surface are planar surfaces. Example 49. A laser configured to direct a beam of light onto a target area; an electron spectrometer configured to receive electrons emitted from the target area in response to receiving the light beam; The quantum control device according to any one of Example 1 or Examples 2 to 48, comprising: Example 50. The quantum control device of example 49, comprising an optical spectrometer configured to receive photons from the target region. Example 51. A semiconductor device comprising an optical waveguide defined by an insulating layer, a field-responsive layer, a cavity, or any combination thereof; The optical waveguide is configured to propagate photons that couple to a quantum state of the target region. The quantum control device according to any one of Example 1 or Examples 2 to 50.

[0098] The quantum control method can also be illustrated by the following example: Example 52. Generating an electric field from protrusions on a substrate, the protrusions extending from a substrate surface of the substrate into a cavity defined by an insulator layer, the insulator layer being disposed over the substrate surface and comprising an insulator surface defining an opening into the cavity; subjecting a field to a target region of a field-responsive layer, the field-responsive layer being disposed on the insulating layer, the target region being positioned over an opening of the cavity; controlling an electric field to interact with a quantum state of a target region of a field-responsive layer; A quantum control method comprising: Example 53. Generating an electric field at the protrusions includes concentrating the electric field using tips of the protrusions; Subjecting the electric field at the target region includes subjecting the electric field to a focused electric field at the target region. The quantum control method of Example 52. Example 54. A concentrated electric field is at least 1 × 10 5 The quantum control method of example 53, having a magnitude of V / m. Example 55. A focused electric field has a magnitude of at least 1 × 10 9 The quantum control method of example 53, having a magnitude of V / m. Example 56. Generating an electric field from a protrusion applying a voltage to electrical contacts below the substrate opposite the base of the projections; transmitting a voltage through the substrate to the protrusions; The quantum control method according to any one of Example 52 and Examples 53 to 55. Example 57. Transmitting an electrical signal from the protrusion to an electrical contact below the substrate and opposite the base of the protrusion, the electrical signal characterizing a quantum state of the target region. The quantum control method according to any one of Example 52 and Examples 53 to 56, comprising: Example 58. The substrate surface is a first substrate surface, and the substrate includes a second substrate surface opposite the first substrate surface; Generating an electric field from the protrusions receiving the light beam at a light concentrating structure opposite a base of the protrusion, the light concentrating structure being formed on a second substrate surface; and guiding the light to the protrusion using a light-concentrating structure. The quantum control method according to any one of Example 52 and Examples 53 to 57. Example 59. Receiving light at a target area of ​​a field-responsive layer The quantum control method according to any one of Example 52 and Examples 53 to 58, comprising: Example 60. Receiving electrons emitted from a target region in response to a light beam in an electron spectrometer. The quantum control method of example 59, comprising: Example 61. A quantum control method described in Example 52 or any of Examples 53-60, wherein controlling the electric field to interact with the quantum state includes varying the magnitude of the electric field to modify the quantum state of the target region of the field-responsive layer. Example 62. Transferring electrons from a protrusion to a target area of ​​a field-responsive layer while generating an electric field. The quantum control method according to any one of Example 52 and Examples 53 to 61, comprising: Example 63. A quantum control method according to any of Example 52 or Examples 53-62, wherein the tip is positioned within the cavity less than 100 nm from the target region. Example 64. A quantum control method according to any of Example 52 or Examples 53-62, wherein the tip is positioned within the cavity less than 20 nm from the target region. Example 65. The quantum control method according to any one of Example 52 or Example 53 to Example 64, wherein the protrusion is formed of a material having a work function of at least 4.0 eV. Example 66. The quantum control method of any of Examples 52 or 53-65, wherein the protrusion has a height to width ratio in the range of 2:1 to 10,000:1. Example 67. The quantum control method of any of Example 52 or Examples 53-66, wherein the target region comprises an intrusion in the atomic structure of the field-responsive layer. Example 68. The quantum control method of any of Example 52 or Examples 53-67, wherein the target region comprises a substitution in the atomic structure of the field-responsive layer. Example 69. The quantum control method of any of Example 52 or Examples 53-68, wherein the target region comprises a void in the atomic structure of the field-responsive layer. Example 70. The quantum control method of any of Example 52 or Examples 53-69, wherein the target region comprises an atom or molecule on the surface of the field-responsive layer. Example 71. The quantum control method of example 70, wherein the atoms or molecules are disposed on an outer surface of the field-responsive layer. Example 72. The quantum control method of example 70, wherein the atoms or molecules are disposed on an inner surface of the field-responsive layer. Example 73. Propagating photons in an optical waveguide defined by an insulating layer, a field-responsive layer, a cavity, or any combination thereof; coupling photons into a quantum state of a target region; The quantum control method according to any one of Example 52 and Examples 53 to 79, comprising:

[0099] A quantum control device comprising an array of protrusions can also be illustrated by the following example: Example 74. A substrate and an insulating layer defining an array of cavities; a field-responsive layer overlying the insulator layer, the field-responsive layer comprising an array of target areas each aligned with a corresponding cavity; a projection extending from the substrate into a corresponding cavity, each projection being interacting with the quantum state of the target region in close proximity to the protrusion; a protrusion configured to generate an electric field that controls quantum coupling between a quantum state of a target region and a quantum state of an adjacent target region; A quantum control device comprising: Example 75. The quantum control device of example 74, wherein the distance between adjacent target regions is 700 nm or less. Example 76. The quantum control device of example 74 or 75, wherein the at least one protrusion comprises a subset of protrusions each producing a corresponding electric field that defines a portion of the electric field. Example 77. A quantum control device as described in example 74 or example 75 or 76, wherein each protrusion terminates in a tip positioned less than 100 nm from the adjacent target region within the corresponding cavity. Example 78. A quantum control device as described in example 74 or example 75 or 76, wherein each protrusion terminates in a tip positioned less than 20 nm from the adjacent target region within the corresponding cavity. Example 79. The quantum control device of any one of Example 74 or Example 75 to Example 78, wherein each protrusion is formed of a material having a work function of at least 4.0 eV. Example 80. The quantum control device of any of Examples 74 or 75-79, wherein each protrusion has a height-to-width ratio in the range of 2:1 to 10,000:1. Example 81. A quantum control device as described in any of Example 74 or Examples 75-80, wherein each protrusion terminates in a tip configured to concentrate the electric field generated by the protrusion. Example 82. The tip provides an electric field of at least 1×10 5 The quantum control device of example 81, which is focused to a magnitude of V / m. Example 83. The tip provides an electric field of at least 1×10 9 The quantum control device of example 81, which is focused to a magnitude of V / m. Example 84. A quantum control device as described in any of Examples 74 or 75-83, wherein the substrate, the insulator layer, and the field-responsive layer define an enclosed space within each cavity, the enclosed space comprising a first clearance volume between a corresponding protrusion and the insulator layer. Example 85. The quantum control device of example 84, wherein the enclosed space comprises a second clearance volume between the tip of the corresponding protrusion and the field-responsive layer. Example 86. Confined space is 10 -5 86. The quantum control device of example 84 or 85, confined to a vacuum pressure of less than 1000 MPa. Example 87. The quantum control device of example 84 or example 85 or 86, wherein the enclosed space is at least partially filled with a dielectric material. Example 88. The quantum control device of any of Example 74 or Examples 75-87, wherein at least one target region comprises an intrusion in the atomic structure of the field-responsive layer. Example 89. A quantum control device as described in any of Example 74 or Examples 75-87, wherein each target region comprises an intrusion in the atomic structure of the field-responsive layer, the intrusions collectively defining an array of intrusions aligned with the array of target regions. Example 90. The quantum control device of any of Example 74 or Examples 75-89, wherein at least one target region comprises a substitution in the atomic structure of the field-responsive layer. Example 91. A quantum control device as described in any of Example 74 or Examples 75-89, wherein each target region comprises a substitution in the atomic structure of the field-responsive layer, the substitutions collectively defining an array of substitutions aligned with the array of target regions. Example 92. The quantum control device of any of Example 74 or Examples 75-91, wherein at least one target region comprises a void in the atomic structure of the field-responsive layer. Example 93. A quantum control device as described in any of Example 74 or Examples 75-91, wherein each target region comprises a void in the atomic structure of the field-responsive layer, the voids collectively defining an array of voids aligned with the array of target regions. Example 94. A quantum control device according to any of Example 74 or Examples 75-93, wherein at least one target region comprises an atom or molecule on the surface of the field-responsive layer. Example 95. The quantum control device of example 94, wherein the atoms or molecules are disposed on an outer surface of the field-responsive layer. Example 96. The quantum control device of example 94, wherein the atoms or molecules are disposed on an inner surface of the field-responsive layer. Example 97. A quantum control device described in any of Example 74 or Examples 75-93, wherein each target region comprises atoms or molecules on a surface of the field-responsive layer, the atoms or molecules collectively defining an array of atoms or molecules aligned with the array of target regions. Example 98. The quantum control device of any of Example 74 or Examples 75-97, wherein the field-responsive layer comprises a layer of graphene. Example 99. An addressing layer underlying a substrate, the addressing layer including electrical contacts configured to receive a voltage signal, each electrical contact aligned with a corresponding protrusion. The quantum control device according to any one of Example 74 and Examples 75 to 98. Example 100. A quantum control device as described in Example 99, wherein each electrical contact is configured to deliver a corresponding voltage signal to the substrate independent of the other electrical contacts, and the substrate is configured to transmit the corresponding voltage signal to a protrusion aligned with the electrical contact to produce a corresponding electric field. Example 101. A quantum control device as described in Example 99 or 98, wherein each electrical contact is configured to receive an electrical signal from the substrate independent of the other electrical contacts, the electrical signal characterizing a quantum state of a target region proximate the projection aligned with the electrical contact, and the substrate is configured to transmit the electrical signal from the aligned projection to the electrical contact. Example 102. At least one protrusion comprises a subset of the protrusions (or a subset of the protrusions of example 76); The quantum control device comprises an addressing layer underlying the substrate, the addressing layer comprising a plurality of electrical contacts, each of which is aligned with a corresponding subset of the protrusions and configured to receive a voltage signal related to the corresponding subset of the protrusions; The quantum control device according to any one of Example 74 and Examples 75 to 101. Example 103. The quantum control device of Example 102, wherein each electrical contact is configured to deliver a corresponding voltage signal to the substrate independent of the other electrical contacts, and the substrate is configured to transmit the corresponding voltage signal to a subset of the protrusions aligned with the electrical contacts to produce a corresponding electric field (or the corresponding electric field of Example 76). Example 104. a laser system configured to direct a laser signal to an array of target areas; an electron spectrometer configured to receive electrons emitted from the array of target areas in response to a laser signal; The quantum control device of any one of Example 74 and Examples 75 to 103, comprising: Example 105. An array of light-concentrating structures beneath a substrate, each aligned to be opposite a corresponding cavity and configured to guide light to a protrusion associated with the corresponding cavity. The quantum control device of any one of Example 74 and Examples 75 to 104, comprising: Example 106. A conductive layer comprising voids arranged along a periodic lattice, the periodic lattice having first regions occupied by the voids and second regions not occupied by the voids, the second regions aligned to be on opposite sides of the array of cavities. The quantum control device according to any one of Example 74 and Examples 75 to 105. Example 107. The quantum control device of example 106, wherein the conductive layer is below the substrate. Example 108. The quantum control device of example 106, wherein the conductive layer is on the field-responsive layer. Example 109. A quantum control device as described in any of Examples 74 or 75-108, comprising a plurality of trenches formed in the substrate and positioned to isolate individual protrusions extending from the substrate. Example 110. A quantum control device as described in any of Examples 74 or 75-108, comprising a plurality of trenches formed in the substrate and arranged to isolate a subset of the protrusions (or a subset of the protrusions of Examples 76 or 102) extending from the substrate, each subset being associated with a single cavity. Example 111. A semiconductor device comprising an optical waveguide defined by an insulating layer, a field-responsive layer, one or more cavities, or any combination thereof; The optical waveguide is associated with the at least one target region and is configured to propagate photons that couple to a quantum state of the at least one target region. The quantum control device according to any one of Example 74 and Examples 75 to 110.

[0100] The quantum control method based on an array of protrusions can also be illustrated by the following example: Example 112. A quantum control method, comprising: generating one or more electric fields from an array of protrusions on a substrate, each electric field being generated by one or more protrusions extending from the substrate into a corresponding cavity in an insulator layer, the corresponding cavity being part of an array of cavities defined by the insulator layer, the insulator layer being disposed above the substrate and below the field-responsive layer; subjecting one or more electric fields at corresponding target regions in the field-responsive layer, the corresponding target regions being part of an array of target regions in the field-responsive layer, each target region having a quantum state and aligned with a corresponding cavity in the array of cavities; controlling one or more electric fields to cause a first quantum state of a first target region to interact with at least a second quantum state of a second target region. Example 113. The quantum control method of example 112, wherein subjecting one or more electric fields includes establishing discrete energy levels of a quantum state for at least one of the corresponding target regions. Example 114. The quantum control method of example 113, wherein all of the corresponding target regions have quantum states with discrete energy levels. Example 115. The quantum control method of example 113 or 114, wherein the discrete energy levels include electronic energy levels. Example 116. The quantum control method of example 113 or example 114 or 115, wherein the discrete energy levels include photon energy levels. Example 117. The quantum control method of example 112, wherein controlling the one or more electric fields includes altering quantum coupling between a first quantum state of a first target region and a second quantum state of a second target region. Example 118. A quantum control method according to any one of Example 112 or Examples 113-117, wherein the first target region is adjacent to the second target region. Example 119. A quantum control method according to any one of Example 112 or Examples 113 to 118, wherein the distance between adjacent target regions is 700 nm or less. Example 120. A quantum control method described in any of Example 112 or Examples 113-119, wherein each protrusion of the array of protrusions terminates in a tip that is positioned within the cavity less than 100 nm from a target area associated with the cavity. Example 121. A quantum control method described in any of Example 112 or Examples 113-119, wherein each protrusion of the array of protrusions terminates in a tip that is positioned within the cavity less than 20 nm from a target region associated with the cavity. Example 122. The quantum control method of any one of Example 112 or Examples 113 to 121, wherein each protrusion of the array of protrusions is formed of a material having a work function of at least 4.0 eV. Example 123. The quantum control method of any of Example 112 or Examples 113-122, wherein each protrusion of the array of protrusions has a height-to-width ratio in the range of 2:1 to 10,000:1. Example 124. The quantum control method of any of Example 112 or Examples 113-123, wherein at least one target region comprises an intrusion in the atomic structure of the field-responsive layer. Example 125. A quantum control method described in any of Example 112 or Examples 113-123, wherein each target region comprises an intrusion in the atomic structure of the field-responsive layer, the intrusions collectively defining an array of intrusions aligned with the array of target regions. Example 126. The quantum control method of any of Example 112 or Examples 113-125, wherein at least one target region comprises a substitution in the atomic structure of the field-responsive layer. Example 127. A quantum control method described in any of Example 112 or Examples 113-125, wherein each target region comprises a substitution in the atomic structure of the field-responsive layer, the substitutions collectively defining an array of substitutions aligned with the array of target regions. Example 128. The quantum control method of any of Example 112 or Examples 113-127, wherein at least one target region comprises a void in the atomic structure of the field-responsive layer. Example 129. A quantum control method described in any of Example 112 or Examples 113-127, wherein each target region comprises a void in the atomic structure of the field-responsive layer, the voids collectively defining an array of voids aligned with the array of target regions. Example 130. A quantum control device according to any of Example 112 or Examples 113-129, wherein at least one target region comprises an atom or molecule on a surface of the field-responsive layer. Example 131. The quantum control method of example 130, wherein the atoms or molecules are disposed on an outer surface of the field-responsive layer. Example 132. The quantum control method of example 130, wherein the atoms or molecules are disposed on an inner surface of the field-responsive layer. Example 133. A quantum control method described in any of Example 112 or Examples 113-130, wherein each target region comprises atoms or molecules on a surface of the field-responsive layer, and the atoms or molecules collectively define an array of atoms or molecules aligned with the array of target regions. Example 134. Propagating photons in an optical waveguide defined by an insulating layer, a field-responsive layer, a cavity of an array of cavities, or any combination thereof; coupling photons into a quantum state of at least one target region of an array of target regions; The quantum control method according to any one of Example 112 and Examples 113 to 133, comprising:

[0101] Although this specification contains many details, they should not be understood as limiting the scope of what may be claimed, but as a description of features specific to a particular example. Certain features described in this specification or shown in the drawings in the context of separate implementations may also be combined. Conversely, various features that are described or shown in the context of a single implementation may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0102] Similarly, although the figures depict operations in a particular order, this should not be construed as requiring such operations to be performed in the particular order or sequence shown, or to perform all of the operations shown, in order to achieve all desired results. In certain situations, multitasking and parallel processing may be advantageous. Still further, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the program components and systems described may be generally integrated together in a single product or packaged into multiple products.

[0103] Although several embodiments have been described, it will be understood that various modifications may be made and, therefore, other embodiments are within the scope of the following claims.

Claims

1. A substrate; an insulating layer defining an array of cavities; a field-responsive layer overlying the insulator layer, the field-responsive layer comprising an array of target areas each aligned with a corresponding cavity; a projection extending from the substrate into a corresponding cavity, each projection comprising: interacting with a quantum state of a target region proximate said protrusion; a protrusion configured to generate an electric field that controls quantum coupling between the quantum state of the target region and a quantum state of an adjacent target region; A quantum control device comprising:

2. The quantum control device of claim 1 , wherein the distance between adjacent target regions is 700 nm or less.

3. The quantum control device of claim 1 , wherein each protrusion terminates in a tip that is positioned less than 100 nm from the proximal target region within the corresponding cavity.

4. The quantum control device of any one of claims 1 to 3, wherein each protrusion terminates in a tip configured to concentrate the electric field produced by the protrusion.

5. The quantum control device of any one of claims 1 to 3, wherein at least one target region comprises an interstitial portion in the atomic structure of the field-responsive layer.

6. The quantum control device of any one of claims 1 to 3, wherein at least one target region comprises a substitution in the atomic structure of the field-responsive layer.

7. The quantum control device of any one of claims 1 to 3, wherein at least one target region comprises a void in the atomic structure of the field-responsive layer.

8. The quantum control device of any one of claims 1 to 3, wherein at least one target region comprises an atom or molecule on a surface of the field-responsive layer.

9. The quantum control device of any one of claims 1 to 3, wherein the field-responsive layer comprises a layer of graphene.

10. an addressing layer underlying the substrate, the addressing layer including electrical contacts configured to receive a voltage signal, each electrical contact aligned with a corresponding protrusion; The quantum control device according to any one of claims 1 to 3.

11. a laser system configured to direct a laser signal to the array of target areas; an electron spectrometer configured to receive electrons emitted from the array of target areas in response to the laser signal; The quantum control device according to any one of claims 1 to 3, comprising:

12. an array of light-concentrating structures underlying the substrate, each aligned opposite a corresponding cavity and configured to guide light to a protrusion associated with the corresponding cavity; The quantum control device according to any one of claims 1 to 3, comprising:

13. a conductive layer having voids arranged along a periodic lattice, the periodic lattice having first portions occupied by voids and second portions not occupied by voids, the second portions being aligned to be on opposite sides of the array of cavities; The quantum control device according to any one of claims 1 to 3.

14. 4. The quantum control device of claim 1, further comprising a plurality of trenches formed in the substrate and arranged to separate individual protrusions extending from the substrate.

15. an optical waveguide defined by the insulator layer, the field-responsive layer, one or more cavities, or any combination thereof; the optical waveguide is associated with at least one target region and configured to propagate photons that couple to a quantum state of the at least one target region. The quantum control device according to any one of claims 1 to 3.

16. A quantum control method, comprising: generating one or more electric fields from an array of protrusions on a substrate, each electric field being generated by one or more protrusions extending from the substrate into a corresponding cavity in an insulator layer, the corresponding cavity being part of an array of cavities defined by the insulator layer, the insulator layer being disposed above the substrate and below a field-responsive layer; subjecting the one or more electric fields at corresponding target regions in the field-responsive layer, the corresponding target regions being part of an array of target regions in the field-responsive layer, each target region having a quantum state and aligned with a corresponding cavity in the array of cavities; controlling the one or more electric fields to cause a first quantum state of a first target region to interact with at least a second quantum state of a second target region.

17. 17. The quantum control method of claim 16, wherein subjecting the one or more electric fields comprises establishing discrete energy levels of a quantum state for at least one of the corresponding target regions.

18. 20. The method of quantum control of claim 17, wherein the discrete energy levels include electronic energy levels.

19. 20. The quantum control method of claim 17, wherein the discrete energy levels include photon energy levels.

20. 17. The quantum control method of claim 16, wherein controlling the one or more electric fields comprises altering quantum coupling between the first quantum state of the first target region and the second quantum state of the second target region.

21. A method for quantum control according to any one of claims 16 to 20, wherein at least one target region comprises an intrusion in the atomic structure of the field-responsive layer.

22. A method for quantum control according to any one of claims 16 to 20, wherein at least one target region comprises a substitution in the atomic structure of the field-responsive layer.

23. A method of quantum control according to any one of claims 16 to 20, wherein at least one target region comprises a void in the atomic structure of the field-responsive layer.

24. A method of quantum control according to any one of claims 16 to 20, wherein at least one target region comprises an atom or molecule on a surface of the field-responsive layer.

25. 21. The quantum control method of any one of claims 16 to 20, wherein each target region comprises atoms or molecules on a surface of the field-responsive layer, the atoms or molecules collectively defining an array of atoms or molecules aligned with the array of target regions.

26. propagating photons in an optical waveguide defined by the insulator layer, the field-responsive layer, a cavity in the array of cavities, or any combination thereof; coupling the photons into a quantum state of at least one target area of ​​the array of target areas; The quantum control method according to any one of claims 16 to 20, comprising:

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