Two cubit gates between multimode cubits with adjustable magnetic flux.

Abstract

The electronic structure may include a first superconducting quantum interference device (SQUID) coupled between the first and second pads of a first tunable coupler qubit (TCQ) having a first qubit, and a first Josephson junction (JJ) coupled between the second and third pads of the first TCQ. The electronic structure may also include a second SQUID coupled between the first and second pads of a second TCQ having a second qubit, and a second JJ coupled between the second and third pads of the second TCQ. The second pad of the first TCQ may be coupled to the second pad of the second TCQ. The first TCQ may be coupled to a first drive line, and the second TCQ may be coupled to a second drive line.

Description

[Background technology]

[0001] This disclosure relates to quantum circuits, and more specifically to two-qubit gates between flux-tunable multimode qubits. [Overview of the project]

[0002] The following is an overview to provide a basic understanding of one or more embodiments of the disclosed subject matter. This overview is not intended to identify key or important elements or to define any scope of any particular embodiment or any scope of any claim. Its sole purpose is to present the concepts in a simplified form as a prelude to the more detailed description to be presented later. In one or more embodiments described herein, systems, devices, structures, methods, apparatus and / or computer program products are presented that can facilitate the formation and / or utilization of two-qubit gates between flux-tunable multimode qubits.

[0003] According to the embodiment, the system may include a first superconducting quantum interference device (SQUID) coupled between the first and second pads of a first tunable coupler qubit (TCQ). The first TCQ may also include a first Josephson junction (JJ) coupled between the second and third pads of the first TCQ. Additionally, the system may include a second SQUID coupled between the first and second pads of a second TCQ. The second TCQ may include a second JJ coupled between the second and third pads of the second TCQ. Furthermore, the second pad of the first TCQ may be coupled to the second pad of the second TCQ. The first TCQ may be coupled to a first drive line, and the second TCQ may be coupled to a second drive line.

[0004] According to another embodiment, the system may include a first drive line that can be coupled to a first TCQ including a first qubit. The system may further include a second drive line coupled to a second TCQ including a second qubit. A first magnetic flux may be applied to the first TCQ via the first drive line, and a second magnetic flux may be applied to the second TCQ via the second drive line, thereby allowing a control phase gate to be coupled between the first and second TCQs.

[0005] According to another embodiment, a method for coupling multiple multimode cubits may include the step of longitudinally coupling a first adjustable coupler cubit (TCQ) to a second adjustable coupler cubit (TCQ), thereby operating the first TCQ with a first flux via a first drive line and the second TCQ with a second flux via a second drive line, thereby forming a ZZ coupling between them, where the first and second TCQs may have direct capacitive coupling between the first central pad of the first TCQ and the second central pad of the second TCQ.

[0006] The advantages of the system may include the ability to enhance connections between quantum components (e.g., qubits or other quantum components) (e.g., increase, improve, or optimize them), enhance the electronic elements of the quantum circuit or the layout of the quantum components, reduce the number of drive lines coupled to TCQ components (e.g., so that one drive line is coupled to each TCQ or qubit), and enhance the management of interactions or couplings between quantum components (which may include enhanced relaxation or suppression of undesirable interactions, couplings, and entanglements between quantum components).

[0007] In some embodiments, elements described in relation to the disclosed system may be embodied in different forms, such as devices, methods, or other forms.

[0008] These and other features will become apparent from the following detailed description of the exemplary embodiment, which should be read in conjunction with the attached drawings. [Brief explanation of the drawing]

[0009] [Figure 1] A block diagram of an exemplary, non-limiting system may include pairs of quantum components and drivelines capable of controlling interactions or couplings between quantum components, according to various aspects and embodiments of the disclosed subject matter.

[0010] [Figure 2] Block diagrams of non-restrictive mode structures illustrating modes of quantum components according to various aspects and embodiments of the disclosed subject matter are shown.

[0011] [Figure 3A] Diagrams of exemplary, non-limiting systems, which may include pairs of quantum components capable of managing interactions or couplings between qubits, are provided for various aspects and embodiments of the disclosed subject matter.

[0012] [Figure 3B] We present illustrative, non-limiting graph diagrams illustrating various modes of magnetic field tuning for a system in a first state, which may include pairs of quantum components capable of controlling the interaction or coupling between qubits, according to various aspects and embodiments of the disclosed subject matter.

[0013] [Figure 3C] We present illustrative, non-limiting graph diagrams illustrating various modes of magnetic field tuning for a system in a second state, which may include pairs of quantum components capable of controlling the interaction or coupling between qubits, according to various aspects and embodiments of the disclosed subject matter.

[0014] [Figure 3D]Present an illustrative non - limiting graph diagram showing various modes of magnetic field adjustment for a system in a third state that may include a pair of quantum components capable of managing interactions or couplings between qubits, according to various aspects and embodiments of the disclosed subject matter.

[0015] [Figure 4] Present an illustrative non - limiting graph diagram showing the interactions between three transmon charge qubits (TCQs) associated with various modes when one of the TCQs can be flux - tuned to transition to an on - state while the other TCQs can be maintained in an off - state, according to various aspects and embodiments of the disclosed subject matter.

[0016] [Figure 5] Present an illustrative non - limiting graph diagram showing the interactions between three TCQs associated with various modes when two of the TCQs can be flux - tuned to an on - state, according to various aspects and embodiments of the disclosed subject matter.

[0017] [Figure 6] Show a flow diagram of an illustrative non - limiting method that can utilize a drive line and a pair of TCQs to control interactions, couplings, or gates between TCQs, according to various aspects and embodiments of the disclosed subject matter.

[0018] [Figure 7] Show a block diagram of an illustrative non - limiting operating environment in which one or more embodiments described herein can be facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following detailed description is merely exemplary and is not intended to limit embodiments and / or the application or use of embodiments. Further, it is not intended to be limited by any of the representations or suggested information presented in the above Background or Summary of the Invention sections, or the Detailed Description of the Invention section.

[0020] Herein, one or more embodiments will be described with reference to the drawings, in which similar reference numerals are used throughout to refer to similar elements. For illustrative purposes, numerous specific details will be included in the following description to provide a more complete understanding of one or more embodiments. However, it will be apparent that in various cases one or more embodiments may be carried out without these specific details.

[0021] A quantum computer may include a group of qubits capable of performing quantum operations on data. In a quantum circuit containing qubits, couplers can be used to enable interaction between qubits or coupling between pairs of qubits, thereby creating quantum logic gates. Couplers may also be used to enable interaction or coupling between other types of electronic elements within a quantum circuit.

[0022] With respect to interactions, coupling, and gates, in order to facilitate the description of various aspects and embodiments of the disclosed subject matter, the following definitions and / or contexts that may be relevant to the disclosed subject matter may be provided. An entanglement gate may include an operation in which an external field (e.g., a microwave pulse) is applied to a quantum processor containing qubits to create an entangled state between two or more separate qubits. A controlled-phase (CPHASE) gate may be a particular type of entanglement gate in which one qubit can acquire a phase shift only when and only when both qubits are in the initial excited state.

[0023] A ZZ interaction may be a type of interaction between two qubits or modes in which the excitation of one qubit can shift the transition frequency of the other qubit or mode. Thus, a ZZ interaction can represent a way of entangling two different qubits to create a CPHASE gate, as a state-dependent shift of qubit frequency can be equivalent to a state-dependent phase shift. A ZZ interaction may sometimes be called a longitudinal coupling, or it may be denoted as chi or 2-chi. A static ZZ interaction may be a type of ZZ interaction that can exist between two qubits or modes in the absence of any external microwave drive (e.g., a microwave pulse). A static ZZ interaction may be an "always-on" interaction that can be undesirable (e.g., unnecessary) and harmful to a qubit system by hindering the independent control of each qubit and creating undesirable entanglement.

[0024] An exchange interaction may be a type of interaction between quantum systems that allows for the exchange of energy. If it exists between two qubits, applying a microwave pulse to one qubit could potentially excite the other, and such an interaction could be an undesirable form of crosstalk that could be detrimental to the quantum system.

[0025] For some existing quantum circuits and couplers, even in the absence of any external microwave drive, there may be always-on interactions between two qubits or modes, such as static ZZ interactions. Such always-on interactions can be undesirable and detrimental to a qubit system because they can hinder the independent control of each qubit and create undesirable (e.g., unnecessary) entanglement between qubits.

[0026] It may be desirable to enhance the efficiency, reliability, and performance of coupler components (e.g., increase, improve, or optimize them), enhance connectivity between qubits (or other quantum components), and improve the layout of electronic elements in quantum circuit configurations. It may also be desirable to enhance the management of interactions and couplings between qubits (or other quantum components), including mitigating or suppressing undesirable interactions, couplings, and entanglements between qubits (or other quantum components).

[0027] The disclosed subject matter includes TCQ components and techniques that may have multiple advantages and may overcome various shortcomings of existing TCQs and techniques. Compared to existing couplers and techniques, the disclosed TCQ components and techniques for coupling TCQs may have enhanced (e.g., increased, improved, or optimized) efficiency, reliability, and performance; may enhance connections between qubits (or other quantum components); may enhance the layout of electronic elements of quantum circuits; may reduce the number of drive lines coupled to the TCQ component (e.g., so that a single drive line is coupled to each TCQ or qubit); and may enhance the management of interactions and couplings between qubits (including enhanced mitigation or suppression of undesirable interactions, couplings, and entanglements between qubits (or other quantum components)).

[0028] To achieve this objective, the various embodiments described herein relate to techniques for controlling the coupling between cubits. In some embodiments, the system or device may include a first adjustable coupler cubit (TCQ) which may include a first mode (e.g., a first "A" mode) associated with a first frequency (e.g., a first mode of vibration) and a second mode (e.g., a first "B" mode) associated with a second frequency (e.g., a second mode of vibration). The TCQ may also be referred to as a TCQ coupler. The system or device may also include a second TCQ which may include a third mode (e.g., a second "B" mode) associated with a third frequency (e.g., a third mode of vibration) and a fourth mode (e.g., a second "A" mode) associated with a fourth frequency (e.g., a fourth mode of vibration). The first TCQ and the second TCQ may be associated with each other (e.g., selectively connected or coupled) as described herein, for example, by direct capacitive coupling, through bus components, or through coplanar waveguides (CPWs).

[0029] Each frequency associated with each mode may be the same as or different from one another. For example, the first frequency associated with a first mode (e.g., the first "A" mode) may be the same as or different from the third frequency associated with a third mode (e.g., the second "A" mode), and the second frequency associated with a second mode (e.g., the first "B" mode) may be the same as or different from the fourth frequency associated with a fourth mode (e.g., the second "B" mode).

[0030] Each flux can be applied to a first TCQ (e.g., a flux-adjustable SQUID of the first TCQ) and a second TCQ (e.g., a flux-adjustable SQUID of the second TCQ), resulting in a desirable balance between the respective modes of each TCQ, and the interactions and such fluxes can suppress undesirable coupling between the first and second TCQs. For example, ZZ interactions or coupling between the first and second TCQs, including static ZZ interactions, can preferably be suppressed, and exchange interactions between the first and second TCQs can preferably be suppressed over a wide range of frequencies based on mode-selectable coupling (e.g., using a pair of TCQs such as the first and second TCQs).

[0031] When the respective modified magnetic fluxes are applied to the first and second TCQs and the tuning of each TCQ is adjusted as desired (e.g., by adjusting the tuning of each SQUID in each TCQ), this can cause imbalances in the first and second TCQs (e.g., as described herein), thereby exciting the respective modes of the first and second TCQs, and as a result, a desirable coupling can be formed, where a ZZ interaction, an entangled interaction and gate, and / or a controlled phase (CPHASE) gate can be formed between the first and second TCQs. A coupling may be defined as an interaction between two systems (e.g., between a first system including a first qubit and / or a first TCQ, and between a second system including a second qubit and / or a second TCQ) that is strong enough to create a multi-qubit gate (e.g., between two qubits), and / or a desired exchange of information or energy between two electronic elements (e.g., electronic elements which may be qubits, resonators, or other desired electronic elements or components).

[0032] These and other aspects and embodiments of the disclosed subject matter will now be described with reference to the drawings.

[0033] In embodiments such as those shown in Figure 1, the non-limiting system 100 may include a pair of quantum components (e.g., TCQs). System 100 may include various components and circuit configurations (e.g., quantum components and circuit configurations) that can be arranged to perform one or more desired functions as described herein. System 100 may include, or be part thereof, a multi-qubit device or package that may have variable dimensions (e.g., an integrated circuit (IC) chip in which system 100 may exist may have variable dimensions), the length of the device or package may range, for example, from a few millimeters to tens of millimeters, the width of the device or package may range, for example, from a few millimeters to tens of millimeters, and the thickness may range, for example, from about 1 millimeter (mm) to about 3 mm. It should be recognized and understood that these dimensions of the device or package are exemplary, and according to other embodiments, the device or package may have dimensions different from (e.g., smaller or larger) the exemplary dimensions described herein.

[0034] In some embodiments, system 100 may include a first quantum component 102 and a second quantum component 104 that can be formed as part of a quantum circuit, which may be formed on one or more chip stacks formed on one or more dies (e.g., IC chips). The first quantum component 102 and the second quantum component 104 may be part of a group of quantum components of a quantum computer (e.g., a superconducting quantum computer). In certain embodiments, the first quantum component 102 and the second quantum component 104 may be flux-tunable coupler qubits (TCQs). A TCQ may include, for example, one or more Josephson junctions (JJs) and a shunt capacitor that can be associated with one or more Josephson junctions.

[0035] It may be desirable (e.g., desired, required, or preferred) to manage (e.g., control) the interactions, coupling, and / or gates between quantum components such as a first quantum component 102 and a second quantum component 104. According to various embodiments, the interactions and coupling between the first quantum component 102 and the second quantum component 104 may be enabled and managed via one or more drive lines. One or more drive lines may control and enable quantum component-quantum component (e.g., qubit-qubit) interactions (e.g., interactions between the first quantum component 102 and the second quantum component 104) which may enable quantum logic gates or other desired types of interactions. In some embodiments, the first quantum component 102 and the second quantum component 104 may be coupled to each other using coupling capacitors, such as those more fully described herein.

[0036] According to various embodiments, the first quantum component 102 and the second quantum component 104 may each be a TCQ (e.g., a flux-tunable TCQ). For example, the first quantum component 102 and the second quantum component 104 may be TCQs that allow one or more parameters (e.g., frequency, or another desired parameter) to be preferably tuned (e.g., modified, adjusted, or altered) based on the magnetic flux applied to the first quantum component 102 and the second quantum component 104, respectively, such as those more fully described herein.

[0037] The first quantum component 102 may include JJ110 and SQUID112 (e.g., a flux-adjustable SQUID), where SQUID112 may include JJ114 and JJ116. CC106 may also include capacitor (C)118, which may be a shunt capacitor associated with JJ110 and SQUID112, a capacitor 120 associated with JJ110, and a capacitor 122 associated with SQUID112. The second quantum component 104 may include JJ124 and SQUID126 (e.g., a flux-adjustable SQUID), where SQUID126 may include JJ128 and JJ130. The second quantum component 104 may also include a shunt capacitor 132 that can be associated with JJ124 and SQUID126, a capacitor 134 that can be associated with JJ124, and a capacitor 136 that can be associated with SQUID126. Furthermore, the first quantum component 102 may store quantum information (e.g., qubit information, quantum state information, etc.) in a first mode of oscillation (e.g., A mode, first mode 138), and the second quantum component 104 may store quantum information in a third mode of oscillation (e.g., A mode, third mode 142). In such a manner, the first quantum component 102 (e.g., first TCQ) and the second quantum component 104 (e.g., second TCQ) can be used as qubits by utilizing the first mode 138 and the third mode 142 to store quantum information.

[0038] In the first quantum component 102, JJ110 and SQUID112 may be constructed, designed, and / or arranged relative to each other in a quantum circuit such that multiple modes of vibration may be formed, where the multiple modes may include a first mode of vibration (e.g., "A" mode) 138 and a second mode of vibration (e.g., "B" mode) 140. The first mode of vibration 138 may be associated with a first frequency, and the second mode of vibration 140 may be associated with a second frequency. The second frequency associated with the second mode 140 may typically be higher than the first frequency associated with the first mode 138. The second mode 140 may not typically have a net dipole moment and may therefore also be referred to as a dark mode. The first mode 138 and the second mode 140 may be two distinct modes that can correspond to symmetric and antisymmetric combinations of excitations associated with JJ110 and SQUID112.

[0039] Similarly, in the second quantum component 104, JJ124 and SQUID126 may be constructed, designed, and / or arranged relative to each other in a quantum circuit such that multiple modes of vibration may be formed, where the multiple modes may include a third mode of vibration (e.g., another "B" mode) 142 and a fourth mode of vibration (e.g., another "A" mode) 144. The third mode 142 may be associated with a third frequency, or the third frequency may be the same as or different from the second frequency associated with the second mode 140. The fourth mode 144 may be associated with a fourth frequency, or the fourth frequency may be the same as or different from the first frequency associated with the first mode 138. The third frequency associated with the third mode 142 may usually be higher than the fourth frequency associated with the fourth mode 144. The third mode 142 may not usually have a net dipole moment and may therefore also be referred to as a dark mode. The third mode 142 and the fourth mode 144 may be two distinct modes that can correspond to symmetric and antisymmetric combinations of excitations associated with JJ124 and SQUID126.

[0040] Referring to Figure 2 (along with Figure 1), Figure 2 illustrates a block diagram of an unrestricted mode structure 200 illustrating modes of quantum components (e.g., a first quantum component 102 and a second quantum component 104) according to various aspects and embodiments of the disclosed subject matter. The mode structure 200 may include an "A" mode structure 202 for the "A" mode (e.g., the first mode 138) of the first quantum component 102, and a "B" mode structure 204 for the "B" mode (e.g., the second mode 140).

[0041] The JJ110 and SQUID112 of the first quantum component 102 (e.g., a flux-tunable TCQ) can be associated with (e.g., connected to) the respective capacitor pads (e.g., capacitor plates) of the respective capacitors of the first quantum component 102, such as capacitor pads 206, 208, and 210. In the "A" mode of the first quantum component 102, as shown in the "A" mode structure 202, charge can flow from capacitor pad 210 to capacitor pad 208 (indicated by reference numeral 212), and charge can also flow from capacitor pad 208 to capacitor pad 206 in the same direction (indicated by reference numeral 214). As a result, no net charge accumulates on capacitor pad 208, and the first quantum component (e.g., SQUID112) can be symmetric or asymmetric depending on how the direction of charge is defined. As shown in the "B" mode structure 204, in the "B" mode of the first quantum component 102, charge can flow from capacitor pad 208 to capacitor pad 206 and capacitor pad 210 (indicated by reference numerals 216 and 218, respectively).

[0042] Referring further to Figure 1, in some embodiments, the first quantum component 102 may be selectively coupled to the second quantum component 104 by applying magnetic flux to SQUID 112 and SQUID 126 via one or more drive lines, thereby allowing the ZZ interaction to form a CPHASE gate between the first mode 138 (e.g., mode A of the first quantum component 102) and the third mode 142 (e.g., mode A of the second quantum component 104).

[0043] Using SQUIDs 112 and 126 respectively, the first quantum component 102 and the second quantum component 104 can be preferably tuned to facilitate the excitation or non-excitation of their respective modes (e.g., 138, 140, 142, 144), resulting in controlled interactions, coupling, and gates between the first quantum component 102 and the second quantum component 104.

[0044] To facilitate the tuning of the first quantum component 102 and the second quantum component 104, the system 100 may include a first coil component 146 (e.g., connected to a first drive line 146') that may be associated with and close to the first quantum component 102 and / or SQUID 112, and a second coil component 148 (e.g., connected to a second drive line 148') that may be associated with and close to the second quantum component 104 and / or SQUID 126. The first coil component 146 may be used to apply a desired magnetic field or flux to the first quantum component 102 (e.g., SQUID 112) based on the current supplied to the first coil component 146 via the first drive line 146'. The second coil component 148 may be used to apply a desired magnetic field or flux to the second quantum component 104 (e.g., SQUID 126) based on the current supplied to the second coil component 148 via the second drive line 148'. The magnetic field formed and applied by the second coil component 148 may differ from or be identical to the magnetic flux formed and applied by the first coil component 146, depending in part with the respective properties (e.g., the barrier properties of the JJ, the properties of the material component, the inductance, impedance, or other properties) of the respective components (e.g., the JJ, the SQUID, or other components) of the first quantum component 102 and the second quantum component 104. Furthermore, the first coil component 146 may apply a first magnetic flux to the SQUID 112 via the first drive line 146', and the second coil component 148 may apply a second magnetic flux to the SQUID 126 via the second drive line 148'. The first magnetic flux applied by the first drive line 146' may be substantially identical to or substantially different from the second magnetic flux applied by the second drive line 148'.

[0045] Under a specific magnetic flux applied to the first quantum component 102 and the second quantum component 104, each mode (e.g., 138, 140, 142, 144) may be maintained in a non-excited state or transitioned to one thereto, thereby suppressing coupling between the first quantum component 102 and the second quantum component 104 and / or suppressing interaction or coupling between each component of the system 100 (e.g., between the first quantum component 102 and the second quantum component 104).

[0046] For example, the first coil component 146 can apply a first amount of magnetic flux to the SQUID 112 of the first quantum component 102 via a first drive line 146' which can produce a first energy (e.g., a first Josephson energy) associated with the SQUID 112, and therefore a second energy (e.g., a second Josephson energy) associated with the JJ 110, which is close to, equal to, or substantially similar to the critical current of the SQUID 112 of the first quantum component 102. Additionally, the second coil component 148 can apply to the SQUID 126 of the second quantum component 104 a second amount of magnetic flux capable of generating a critical current for the SQUID 126, and therefore a third energy associated with the SQUID 126 (e.g., a third Josephson energy) that is close to, equal to, or at least substantially similar to the critical current of the JJ 124 of the second quantum component 104, and therefore a fourth energy associated with the JJ 124 (e.g., a fourth Josephson energy). As a result, there may be balancing of first and second energies associated with the first quantum component 102, and balancing of third and fourth energies associated with the second quantum component 104, which can provide and / or implement desirable mode-selectable coupling associated with the first quantum component 102 and the second quantum component 104, thereby producing or forming a desirable suppression (e.g., squelching) of the interaction or coupling (e.g., ZZ, static ZZ, and / or exchange interaction or coupling) between the first quantum component 102 and the second quantum component 104 to essentially or nearly zero interaction or coupling.

[0047] When the magnetic flux applied to SQUID112 and SQUID126 by the first coil component 146 and the second coil component 148 is modified (e.g., altered or adjusted) to specific amounts of magnetic flux, and the tuning of the first quantum component 102 and the second quantum component 104 is adjusted (e.g., the tuning associated with SQUID112 and SQUID126 is adjusted), each mode (e.g., 138, 140, 142, 144) may transition to an excited state, thereby enabling a desired interaction or coupling between the first quantum component 102 and the second quantum component 104 (and the interaction or coupling between the first mode 138, the second mode 140, the third mode 142, and / or the fourth mode 144 for storing and / or transmitting quantum / qubit information).

[0048] For example, but not limited to, the ZZ interaction between the first quantum component 102 and the second quantum component 104 can be activated by applying a first modified flux through the first drive line 146' and a second modified flux through the second drive line 148' (for example, thereby modifying the energies of SQUID 112 and SQUID 126). Furthermore, the second modified flux can be applied to the second quantum component 104 through the second drive line 148' to modify the third energy of SQUID 126 (for example, the Josephson energy, E). JBy reducing the first energy, a ZZ interaction can be activated between the first quantum component 102 and the second quantum component 104. By applying a second modified flux, the third energy can be reduced from approximately 13.13 GHz to approximately 9.75 GHz. By reducing the third energy of SQUID 126, the frequencies of the third mode 142 and the fourth mode 144 of the oscillations can decrease, and the spatial configuration can change (for example, schematically shown in Figures 4, 5, and 6). The ZZ interaction can further be activated between the first quantum component 102 and the second quantum component 104 by applying a first modified flux to the first quantum component 102 via the first drive line 146' to reduce the first energy of SQUID 112. For example, but not limited to, by applying a first modification of the magnetic flux, the first energy can be reduced to a value of approximately 10.5 GHz (for example, this can be demonstrated by varying the Josephson energy, EJ, over a desired sweep range). By applying a second modification of the magnetic flux and the first modification of the magnetic flux, the ZZ interaction between the first quantum component 102 (e.g., the first TCQ) and the second quantum component 104 (e.g., the second TCQ) can be increased to a value greater than approximately 3 MHz (e.g., significantly enhanced), while the ZZ interaction between the additional quantum components coupled to the second quantum component 104 (e.g., as shown in Figure 3) may be lower than approximately 10 kHz. Furthermore, the enhanced ZZ interaction between the first quantum component 102 and the second quantum component 104 may allow a CPHASE gate to be realized / generated between them.

[0049] Referring next to Figure 3A, Figure 3A shows a diagram of an exemplary, non-limiting system 300 that may include a first TCQ, a second TCQ, and a third TCQ (e.g., a third spectator TCQ / qubit for the first and second TCQs) according to various aspects and embodiments of the disclosed subject matter. System 300 may include a first TCQ 302, a second TCQ 304, and a third TCQ 306 that may be formed as part of a quantum circuit that may be formed on one or more chip stacks formed on one or more dies (e.g., IC chips). The first TCQ 302 may be coupled to the second TCQ 304 via direct capacitive coupling (e.g., pad-to-pad) or a CPW resonator (e.g., a coupling element 308 in a pad-and-line-and-pad coupling array). Similarly, the second TCQ304 can be coupled to the third TCQ306 via direct capacitive coupling (e.g., pad-to-pad) or a CPW resonator (e.g., coupling element 310 in a pad-line-pad coupling array).

[0050] With respect to embodiments, the first TCQ302 may include JJ314 and SQUID312 which can be associated with (e.g., connected to) JJ314. The first TCQ302 may include a first pad 330, a second pad 332 (e.g., a central pad), and a third pad 334. SQUID312 may be coupled between the first pad 330 and the second pad 332, and JJ314 may be coupled between the second pad 332 and the third pad 334. The second TCQ304 may include JJ318 which can be associated with (e.g., connected to) JJ318 and SQUID316. The second TCQ304 may include a first pad 336, a second pad 338 (e.g., a central pad), and a third pad 340. SQUID316 may be coupled between the first pad 336 and the second pad 338, and JJ318 may be coupled between the second pad 338 and the third pad 340. The third TCQ306 may include JJ322 (e.g., connected) and SQUID320, which may be associated with JJ322. The third TCQ306 may include the first pad 342, the second pad 344 (e.g., the center pad), and the third pad 346. SQUID320 may be coupled between the first pad 342 and the second pad 344, and JJ322 may be coupled between the second pad 344 and the third pad 346.

[0051] In an embodiment, the SQUID 312 of the first TCQ 302 may be coupled to a first drive line 350. The first drive line 350 may be terminated in a coil substantially adjacent to the SQUID 312, thereby allowing a current flowing through the first drive line 350 to generate a local magnetic field around the SQUID 312. The first drive line 350 may provide a current capable of adjusting the magnetic flux surrounded by the SQUID 312. By changing the Josephson energy of the SQUID 312, the first drive line 350 may change the energy level and symmetry of the associated qubit state (for example, thereby allowing quantum information to be stored in the A mode of the first TCQ 302, the second TCQ 304, and / or the third TCQ 306).

[0052] In the embodiment, the SQUID 316 of the second TCQ 304 may be coupled to a second drive line 352. The second drive line 352 may be terminated in a coil substantially adjacent to the SQUID 316, thereby allowing a current flowing through the second drive line 352 to generate a local magnetic field around the SQUID 316. The second drive line 352 may provide a current capable of adjusting the magnetic flux surrounded by the SQUID 316. By changing the Josephson energy of the SQUID 316, the second drive line 352 may change the energy level and symmetry of the associated qubit state (for example, thereby allowing quantum information to be stored in the A mode of the first TCQ 302, the second TCQ 304, and / or the third TCQ 306).

[0053] In an additional embodiment, the SQUID 320 of the third TCQ 306 may be coupled to a third drive line 354. The third drive line 354 may be terminated in a coil substantially adjacent to the SQUID 316, thereby allowing a current flowing through the third drive line 354 to generate a local magnetic field around the SQUID 320. The third drive line 354 may provide a current capable of adjusting the magnetic flux surrounded by the SQUID 320. By changing the Josephson energy of the SQUID 320, the third drive line 354 may change the energy level and symmetry of the associated qubit state (for example, thereby allowing quantum information to be stored in the A mode of the first TCQ 302, the second TCQ 304, and / or the third TCQ 306).

[0054] In an embodiment, the first TCQ 302 may include a first mode 360 ​​(e.g., "A" mode) associated with a first frequency and a second mode 362 (e.g., "B" mode) associated with a second frequency. The second TCQ 304 may include a third mode 364 (e.g., another "A" mode) associated with a third frequency and a fourth mode 366 (e.g., another "B" mode) associated with a fourth frequency. The third TCQ 306 may include a fifth mode 368 (e.g., another "A" mode) associated with a fifth frequency and a sixth mode 370 (e.g., another "B" mode) associated with a sixth frequency.

[0055] With respect to embodiments such as those schematically shown in Figures 3B, 3C, and 3D, the system 300 can be in a first state, a second state, or a third state. The first state may correspond to an "off" state in which the first and second modifier flux amounts are not applied to the first TCQ 302 or the second TCQ 304 (for example, as schematically shown in Figure 3B). When the system 300 is in the first state, the second mode 362, the fourth mode 366, and the sixth mode 370 may include exchange interactions between them. For example, the second mode 362 of the first TCQ 302 may be coupled to the fourth mode 366 of the second TCQ 304; the fourth mode 366 of the second TCQ 304 may be coupled to the sixth mode 370 of the third TCQ 306. For example, system 300 may include any number of additional quantum components connected in a similar manner to the first TCQ (first quantum component) 302, the second TCQ (second quantum component) 304, and the third TCQ (third quantum component) 306 (e.g., with coupled neighborhood "B modes"). In embodiments, the first mode 360, the third mode 364, and the fifth mode 368 may not be coupled to the additional quantum components or to each other, resulting in negligible crosstalk between the modes (first mode 360, third mode 364, and fifth mode 368).

[0056] Furthermore, in the embodiment shown in Figure 3C, the second state may correspond to an "intermediate" state in which the second correction flux can be applied to the second TCQ304 (e.g., SQUID316), and the first correction flux can be prevented from being applied to the first TCQ302 (e.g., SQUID312). By applying the second correction flux to the second TCQ304 (e.g., SQUID316), the E of SQUID316 J The frequency and energy of the third mode 364 and fourth mode 366 of the second TCQ 304 can be reduced and the spatial configuration of the third mode 364 and fourth mode 366 of the second TCQ 304 can be changed. When system 300 is in the second state, the change in the spatial configuration of the second TCQ 304 may cause the second mode 362 (of the first TCQ 302) to include exchange interactions with the third mode 364 and fourth mode 366 (of the second TCQ 304), as shown by the intermode connection line segments in Figure 3C. By applying a second modified amount of flux to the second TCQ 304, the frequency and energy of the third mode 364 and fourth mode 366 (of the second TCQ 304, e.g., modes A and B of the second TCQ 304) can be reduced.

[0057] In further embodiments, such as those schematically shown in Figure 3D, the third state may correspond to an "on" state in which a second modified flux can be applied to the second TCQ304 and a first modified flux can be applied to the first TCQ302. By applying flux through both the first drive line 146' and the second drive line 148', the ZZ interaction between the first mode 360 ​​(A mode of the first TCQ302) and the third mode 364 (A mode of the second TCQ304) can be enhanced, thereby realizing a CPHASE gate between them. Furthermore, the first drive line 146' may be fitted with a first modified amount of flux, which can be determined by applying sufficient flux such that the third frequency (e.g., the frequency of the A mode of the second TCQ 304) is substantially identical to the transition frequency from the first state to the second excited state of the first TCQ 302 (e.g., within approximately 100 MHz, or substantially identical to the greater or lesser exchange coupling frequency). For example, one or more JJs of system 300 may include a port and a deactivation inductor, from which variables such as s-parameters and impedance can be calculated. Furthermore, Josephson energies may be assigned to various JJs, and system 300 may be quantized to determine the energy levels and ZZ coupling between the various modes of the TCQ (e.g., system 300 is evaluated as a quantum machine system).

[0058] In the example, when system 300 is in the third state, the frequency shift of the first TCQ 302 may result in additional exchange interactions with the first mode 360 ​​and the second mode 362 (of the first TCQ 302, for example). As a result, the first mode 360 ​​may include exchange interactions with the third mode 364 and the fourth mode 366. Additionally, the second mode 362 may include exchange interactions with the third mode 364 and the fourth mode 366. The first mode 360 ​​may include exchange interactions with the fourth mode 366.

[0059] Referring to Figure 4, Figure 4 shows an exemplary diagram of Graph 400 relating to coupling a first TCQ302 to a second TCQ304 (e.g., this is then coupled to a third TCQ306) over a desired sweep range according to various aspects and embodiments of the disclosed subject matter, where they are connected by direct capacitive coupling or CPW. Coupling can be defined as an interaction between two systems (e.g., between a first system including the first TCQ302 and a second system including the second TCQ304) that is strong enough to form a multi-qubit gate (e.g., between two qubits stored in A mode of the first TCQ302 and the second TCQ304), and / or a desired exchange of information or energy between two electronic elements (e.g., qubits, resonators, or other desired electronic elements or components).

[0060] In the embodiment, Graph 400 shows the frequency (F) in GHz associated with the modes of TCQ (e.g., 360, 362, 364, 366, 368, 370), and the Josephson energy E in GHz for the system in the second state ("intermediate" state). j Graph 402 may include the corresponding modes. Graph 400 also shows the Josephson energy E in GHz units. jFigure 4 may include graph 404 relating to the ZZ interaction in kHz units between corresponding TCQs (e.g., 302, 304, 306). The ZZ interaction between the first mode 360 ​​and the third mode 364 is shown by plot 410. Additionally, a similar ZZ interaction can be seen between the third mode 364 and the fifth mode 368, as shown by plot 412; the ZZ interaction between the fifth mode 368 and the first mode 360 ​​may be shown by plot 414. As can be seen from Figure 4, graphs 404 and plot 414 show that there is no coupling between the first TCQ 302 and the third TCQ 306 due to selectable coupling controlled by the first drive lines 146' and the second drive lines 148' that apply magnetic flux to SQUID 312 and SQUID 316. Additionally, the first line segment 416 is the E of the second TCQ304 when the system 100 is in a first state (e.g., the "off" state). J This indicates the second line segment 418 of the second TCQ304 when system 100 is in the second state ("intermediate" state). J As shown, a second modified flux can be applied to the second TCQ304 via the second drive line 148', thereby reducing the EJ of the SQUID316 from about 13.13 GHz to about 9.75 GHz, or more or less.

[0061] In an embodiment, Figure 5 shows an exemplary graph 500 diagram relating to the coupling of a first TCQ302 with a second TCQ304 over a desired sweep range in a third state, according to various aspects and embodiments of the disclosed subject matter. Graph 500 shows the frequency (F) in GHz associated with the modes of the TCQ (e.g., 360, 362, 364, 366, 368, 370) and the Josephson energy E in GHz for the system in a third state ("on" state). j Graph 502 may include the corresponding modes. Graph 400 also shows the Josephson energy E in GHz units. jIt may include a graph 404 regarding the kHz - unit ZZ interaction between TCQs (e.g., 302, 304, 306) according to []. The ZZ interaction between the first mode 360 and the third mode 364 is shown by plot 510. Additionally, as shown by plot 512, a similar ZZ interaction between the third mode 364 and the fifth mode 368 can be seen; the ZZ interaction between the fifth mode 368 and the first mode 360 may be shown by plot 514. The third line segment 516 indicates the E of the first TCQ 302 when the system is in the first state (e.g., the "off" state). J is shown. The fourth line segment 518 indicates the E of the first TCQ 302 when the system is in the third state ("on" state). J is shown. As shown, a first amount of flux modification can be applied to the first TCQ 302 via the second drive line 148', thereby reducing the EJ of the SQUID 312 to about 10.5 GHz, or greater or less. By applying the flux of the first amount of modification, the ZZ interaction between the first TCQ 602 and the second TCQ 604 can be increased to a value greater than about 3 MHz, while the ZZ interaction between the second TCQ 604 and the third TCQ 606 may be less than about 10 kHz. Quantum information (e.g., qubit information) can then be stored in the first mode 360 and the third mode 364 without interference from the fifth mode 368 and / or the sixth mode 370.

[0062] FIG. 6 shows a flow diagram of an exemplary non - limiting method 600 by which a first TCQ can be coupled to a second TCQ according to various aspects and embodiments of the disclosed subject matter, whereby quantum information can be stored in the first mode of the first TCQ and the third mode of the second TCQ. Method 700 can be performed by a system including, for example, a TCQ or pairs of any number of TCQs. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted or may be omitted for brevity.

[0063] In 602, method 600 may include the step of longitudinally coupling a first TCQ to a second TCQ, operating the first TCQ with a first magnetic flux via a first drive line and operating the second TCQ with a second magnetic flux via a second drive line, thereby forming a ZZ coupling between them, wherein the first TCQ and the second TCQ have direct capacitive coupling between the first central pad of the first TCQ and the second central pad of the second TCQ.

[0064] In some embodiments, the first TCQ may include a first mode (A mode, the first vibration mode) and a second mode (B mode, the second vibration mode); similarly, the second TCQ may include a third mode (second A mode, the third vibration mode) and a fourth mode (second B mode, the fourth vibration mode). The first TCQ may include a first SQUID and a first JJ; the second TCQ may include a second SQUID and a second JJ. The first driveline may apply the first flux to the first SQUID of the first TCQ, so that the sum of the critical currents of the first SQUID (e.g., two JJs within the SQUID) is substantially the same as the critical current of the first JJ (e.g., substantially the same means equal to or close to equal to such an extent that, at zero flux, the second and fourth modes of the first and second TCQs can be coupled). Similarly, the second drive line may apply the second flux to the second SQUID of the second TCQ, so that the sum of the critical currents of the second SQUID (e.g., two JJs within the SQUID) is substantially the same as the critical current of the second JJ (e.g., substantially the same means equal to or close to equal to such an extent that the second and fourth modes of the first and second TCQs can be coupled at zero flux). The first TCQ may be selectively coupled to the second TCQ by applying flux to the first and second SQUIDs via the first and second drive lines, so that the ZZ interaction can form a CPHASE gate between the first and third modes.

[0065] Method 600 may include a step of tuning the first TCQ and the second TCQ by applying magnetic flux to the first SQUID and the second SQUID. The first SQUID and the second SQUID may tune the first TCQ and the second TCQ (for example by applying magnetic flux) to facilitate the excitation or non-excitation of their respective modes, resulting in controlled interaction, coupling, and gating between the first TCQ and the second TCQ. The first coil component may apply the first magnetic flux to the first SQUID via the first drive line, and the second coil component may apply the second magnetic flux to the second SQUID via the second drive line. The first and second magnetic fluxes may be substantially identical or substantially different. The first coil component can apply a first amount of magnetic flux to the first SQUID, thereby generating a critical current in the first SQUID. Therefore, the first energy associated with the first SQUID is equal to, or at least substantially equal to, the critical current of the first JJ and the second energy associated with the first JJ. The second coil component can apply a second amount of magnetic flux to the second SQUID, thereby generating a critical current in the second SQUID. Therefore, the third energy associated with the second SQUID is equal to, or at least substantially equal to, the critical current of the second JJ and the fourth energy associated with the second JJ. Method 600 may comprise the steps of balancing a first energy and a second energy associated with a first TCQ, and balancing a third energy and a fourth energy associated with a second TCQ, thereby providing a desirable mode-selectable coupling associated with the first TCQ and the second TCQ. Furthermore, the above energy balancing may result in a desirable suppression of interaction or coupling between the first TCQ and the second TCQ.

[0066] In 604, method 600 may include a step of coupling the second vibration mode of the first TCQ to the fourth vibration mode of the second TCQ at zero flux. For example, but not limited to, the B modes of the first TCQ and the second TCQ may be coupled together (e.g., to a neighboring TCQ via a central pad).

[0067] In 606, method 600 may include a step of storing quantum information (qubit information) in the first vibration mode (A mode) of the first TCQ and the third vibration mode (A mode) of the second TCQ. In such a scheme, the TCQs can be used as qubits in the system (e.g., as the first qubit and the second qubit) and therefore do not require connection to a coupler element for additional control. Furthermore, an advantage of coupling the first drive line to the first SQUID and the second drive line to the second SQUID is that the system may utilize a single drive line (e.g., a flux line) for each qubit (e.g., TCQ) for state manipulation and coupling.

[0068] In 608, method 600 may include the step of applying a second modified flux to the first SQUID of the first TCQ via a second drive line to reduce the frequencies of the third and fourth vibration modes of the second TCQ. The second modified flux is applied to the E of the second TCQ. J This could be a quantity that reduces the value from approximately 13.13 GHz to approximately 9.75 GHz (for example, by reducing the energy level, reducing the frequency, and altering the spatial configuration).

[0069] In 610, Method 600 may include the step of applying a first modified amount of magnetic flux to a first SQUID of a first TCQ via a first drive line, so that the frequency of the first vibration mode of the first TCQ is substantially the same as the transition frequency of the second TCQ. JThe system may include a step to reduce the magnetic flux to a value of approximately 10.5 GHz (or greater or less). By applying a first quantity of magnetic flux to the first TCQ, the ZZ interaction between the first TCQ and the second TCQ can be increased to a value greater than approximately 3 MHz (or greater or less).

[0070] In 612, method 600 may include a step of coupling a control phase gate between a first TCQ and a second TCQ. Furthermore, the ZZ interaction between the first and third vibration modes may be greatly enhanced, thereby providing the CPHASE gate to be realized. In addition, the application of magnetic flux through the first and / or second drive lines may be eliminated / prevented in order to turn off the ZZ interaction between the first and third vibration modes.

[0071] For the sake of simplicity, these methods and / or computer implementations are illustrated and described as a series of actions. The disclosed subject matter is not limited by the actions and / or the order in which they are shown; for example, actions may occur in various orders and / or in parallel, along with other actions not shown and described herein. Furthermore, not all of the actions shown may be necessary to implement a computer implementation in accordance with the disclosed subject matter. Those skilled in the art will also understand and recognize that a computer implementation may alternatively be represented as a series of interconnected states via a state diagram or events. Additionally, it should be further recognized that computer implementations disclosed hereafter and throughout this specification may be stored in a product to facilitate the transfer and transmission of such computer implementations to a computer. As used herein, the term "product" is intended to encompass computer programs accessible from any computer-readable device or storage medium.

[0072] Referring now to Figure 7, further details of additional context are provided for one or more embodiments described herein in Figures 1-6.

[0073] Figure 7 and the following description are intended to provide a general description of a preferred computing environment 700 in which one or more embodiments described in Figures 1-6 herein may be implemented. For example, various aspects of this disclosure are described by explanatory text, flowcharts, block diagrams of computer systems, and / or block diagrams of machine logic included in embodiments of computer program products (CPPs). With respect to any flowchart, depending on the technology involved, it is possible to perform operations in a different order than those shown in a particular flowchart. For example, again depending on the technology involved, two operations shown in consecutive flowchart blocks may be performed in reverse order, as a single integrated stage, simultaneously, or with at least partial time overlap.

[0074] Computer program product embodiment ("CPP embodiment" or "CPP") is a term used in this disclosure to describe any set of one or more storage media (also called "mediums") that collectively comprise a set of one or more storage devices that collectively comprise machine-readable code corresponding to instructions and / or data for performing computer operations specified in a given CPP claim. A "storage device" is any tangible device capable of holding and storing instructions for use by a computer processor. Computer-readable storage media may, but are not limited to, electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, mechanical storage media, or any preferred combination thereof. Some known types of storage devices, including these media, include diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random-access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanically encoded devices (such as pits / lands formed on the main surface of a punch card or disk), or any preferred combination of the above. Computer-readable storage media, when used in this disclosure, should not be interpreted as storage in the form of transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides, optical pulses passing through optical fiber cables, electrical signals transmitted through wires, and / or other transmission media.As those skilled in the art will understand, data is typically moved at several intermittent points during the normal operation of a storage device, such as during access, defragmentation, or garbage collection; however, data is not transient while it is stored, and therefore the storage device is not transient.

[0075] The computing environment 700 includes examples of an environment for executing at least a portion of the computer code associated with performing the method of the invention, such as the transformation of the original source code based on the configuration of the target system by the quantum circuit measurement readout code 780. In addition to block 780, the computing environment 700 includes, for example, a computer 701, a wide area network (WAN) 702, an end-user device (EUD) 703, a remote server 704, a public cloud 705, and a private cloud 706. In this embodiment, the computer 701 includes a processor set 710 (including processing circuits 720 and a cache 721), a communication fabric 711, volatile memory 712, persistent storage 713 (including the operating system 722 and block 780 as identified above), a peripheral device set 714 (including a user interface (UI) device set 723, storage 724, and an Internet of Things (IoT) sensor set 725), and a network module 715. The remote server 704 includes a remote database 730. Public Cloud 705 includes Gateway 740, Cloud Orchestration Module 741, Host Physical Machine Set 742, Virtual Machine Set 743, and Container Set 744.

[0076] Computer 701 may take the form of a desktop computer, laptop computer, tablet computer, smartphone, smartwatch, or other wearable computer, mainframe computer, quantum computer, or any other form of computer or mobile device, currently known or to be developed in the future, that can run programs, access networks, or query databases such as the remote database 730. As is well understood in the field of computer technology, and depending on the technology, the execution of a computer implementation may be distributed among multiple computers and / or multiple locations. On the other hand, in this description of the computing environment 700, in order to keep the explanation as concise as possible, the detailed discussion will focus on a single computer, in particular computer 701. Although computer 701 is not shown in the cloud in Figure 7, it may be located in the cloud. On the other hand, computer 701 is not required to be located in the cloud, except to any extent that may be explicitly shown.

[0077] The processor set 710 includes one or more computer processors of any kind currently known or to be developed in the future. The processing circuits 720 may be distributed across multiple packages, for example, multiple coordinated integrated circuit chips. The processing circuits 720 may implement multiple processor threads and / or multiple processor cores. The cache 721 is memory located within the processor chip package and is typically used for data or code that should be available for high-speed access by threads or cores running on the processor set 710. The cache memory is typically divided into multiple levels depending on its relative proximity to the processing circuits. Alternatively, some or all of the cache for the processor set may be located "off-chip". In some computing environments, the processor set 710 may operate using qubits and be designed to perform quantum computing.

[0078] Computer-readable program instructions are typically loaded onto computer 701, and the computer implementation method is realized by causing the processor set 710 of computer 701 to execute a series of operational steps. As a result, the instructions thus executed instantiate the methods specified in the flowcharts and / or descriptions of the computer implementation methods contained herein (collectively referred to as the "Methods of the Invention"). These computer-readable program instructions are stored in various types of computer-readable storage media, such as the cache 721 and other storage media described later. The program instructions and associated data are accessed by the processor set 710 to control and direct the execution of the Methods of the Invention. In the computing environment 700, at least some of the instructions for executing the Methods of the Invention may be stored in block 780 in persistent storage 713.

[0079] The communication fabric 711 is a signal conduction path that enables various components of the computer 701 to communicate with one another. Typically, this fabric is made up of switches and conductive paths, such as buses, bridges, physical input / output ports, and similar switches and conductive paths. Other types of signal communication paths may be used, such as fiber optic communication paths and / or wireless communication paths.

[0080] Volatile memory 712 is any type of volatile memory currently known or to be developed in the future. Examples include dynamic random-access memory (RAM) or static RAM. Volatile memory is typically characterized by random access, but this is not required unless explicitly stated. In computer 701, volatile memory 712 is located in a single package and resides inside computer 701, but alternatively or additionally, volatile memory may be distributed across multiple packages and / or located externally to computer 701.

[0081] Persistent storage 713 is any form of non-volatile storage for a computer, currently known or to be developed in the future. Non-volatility of this storage means that the stored data is maintained regardless of whether power is supplied directly to the computer 701 and / or to the persistent storage 713. Persistent storage 713 may be read-only memory (ROM), but typically at least a portion of the persistent storage allows for writing, deleting, and rewriting of data. Some well-known forms of persistent storage include magnetic disks and solid-state storage devices. The operating system 722 can take multiple forms, including various known proprietary operating systems or open-source portable operating system interface (CSI) types employing a kernel. The code contained in block 780 typically includes at least a portion of computer code involved in performing the method of the present invention.

[0082] The peripheral device set 714 includes a set of peripheral devices for the computer 701. Data communication connections between the computer 701's peripheral devices and other components can be implemented in various ways, including Bluetooth connections, Near-Field Communication (NFC) connections, connections made by cables (such as universal serial bus (USB) type cables), insert-type connections (e.g., secure digital (SD) cards), connections made through local area communication networks, and even connections made through wide area networks such as the Internet. In various embodiments, the UI device set 723 may include components such as a display screen, speaker, microphone, wearable devices (such as goggles and smartwatches), keyboard, mouse, printer, touchpad, game controller, and haptic devices. Storage 724 is external storage such as an external hard drive, or insertable storage such as an SD card. Storage 724 may be persistent and / or volatile. In some embodiments, storage 724 may take the form of a quantum computing memory device for storing data in the form of qubits. In embodiments where computer 701 is required to have a large amount of storage (for example, when computer 701 locally stores and manages a large database), this storage may be provided by peripheral storage devices designed to store large amounts of data, such as a storage area network (SAN) shared by multiple geographically distributed computers. The IoT sensor set 725 consists of sensors that can be used in Internet of Things applications. For example, one sensor may be a thermometer and another may be a motion detector.

[0083] The network module 715 is a collection of computer software, hardware, and firmware that enables computer 701 to communicate with other computers via the WAN 702. The network module 715 may include hardware such as a modem or Wi-Fi signal transceiver, software for packetizing and / or depacketizing data for communication network transmission, and / or web browser software for communicating data over the internet. In some embodiments, the network control and network forwarding functions of the network module 715 are performed on the same physical hardware device. In other embodiments (e.g., embodiments utilizing software-defined networking (SDN)), the control and forwarding functions of the network module 715 are performed on physically separate devices, so that the control function manages multiple different network hardware devices. Computer-readable program instructions for performing the method of the present invention can typically be downloaded from an external computer or external storage device to computer 701 via a network adapter card or network interface included in the network module 715.

[0084] WAN702 is any wide area network (e.g., the Internet) capable of transmitting computer data over non-local distances by any technology currently known or to be developed for transmitting computer data. In some embodiments, a WAN may be replaced and / or complemented by a local area network (LAN), such as a Wi-Fi network, designed to transmit data between devices located in a local area. WANs and / or LANs typically include computer hardware such as copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and edge servers.

[0085] An end-user device (EUD) 703 is any computer system used and controlled by an end-user (e.g., a customer of the company operating computer 701) and can take any of the forms discussed above in relation to computer 701. EUD 703 typically receives useful and valuable data from the operation of computer 701. For example, in a hypothetical case where computer 701 is designed to provide recommendations to an end-user, these recommendations would typically be transmitted from computer 701's network module 715 to EUD 703 via WAN 702. In this way, EUD 703 can display or otherwise present these recommendations to the end-user. In some embodiments, EUD 703 may be a client device such as a thin client, heavy client, mainframe computer, and / or desktop computer.

[0086] The remote server 704 is any computer system that provides at least some data and / or functionality to computer 701. The remote server 704 may be controlled and used by the same entity that operates computer 701. The remote server 704 represents a machine that collects and stores useful and valuable data for use by other computers, such as computer 701. For example, in a hypothetical case where computer 701 is designed and programmed to provide recommendations based on historical data, this historical data may be provided to computer 701 from the remote database 730 of the remote server 704.

[0087] Public Cloud 705 is any computer system available for use by multiple entities, providing on-demand availability of computer system resources and / or other computing capabilities, particularly data storage (cloud storage) and computing power, without direct, active management by scale. Direct and active management of Public Cloud 705's computing resources is performed by the computer hardware and / or software of Cloud Orchestration Module 741. The computing resources provided by Public Cloud 705 are typically implemented by virtual computing environments running on various computers that make up the host physical machine set 742, the host physical machine set being all the physical computers included in and / or available therein in Public Cloud 705. Virtual computing environments (VCEs) typically take the form of virtual machines in the virtual machine set 743 and / or containers in the container set 744. These VCEs may be stored as images and may be transferred either as images or after instantiation of the VCEs, among and between hosts of various physical machines. The cloud orchestration module 741 manages the transfer and storage of images, deploys newly instantiated VCEs, and manages active instances of the VCE deployment. The gateway 740 is a collection of computer software, hardware, and firmware that enables the public cloud 705 to communicate through the WAN 702.

[0088] Here, we will provide some further explanation of virtual computing environments (VCEs). A VCE can be stored as an "image." From this image, a new active instance of the VCE can be instantiated. Two well-known types of VCEs are virtual machines and containers. A container is a VCE that uses operating system-level virtualization. This refers to an operating system feature in which the kernel allows for the existence of multiple isolated user-space instances called containers. These isolated user-space instances typically behave as actual computers from the perspective of the programs running within them. Computer programs running on a normal operating system can utilize all of that computer's resources, such as connected devices, files and folders, network shares, CPU power, and quantifiable hardware capabilities. However, programs running inside a container can only use the contents of the container and the devices allocated to the container, which is a known feature of containerization.

[0089] Private Cloud 706 is similar to Public Cloud 705, but differs in that its computing resources are available only for use by a single enterprise. While Private Cloud 706 is shown as being in communication with WAN 702, in other embodiments, a private cloud may be completely isolated from the internet and accessible only through a local / private network. A hybrid cloud is a combination of multiple clouds of different types (e.g., private, community, or public cloud types), often implemented by different vendors. Each of the multiple clouds remains a separate, isolated entity, but in larger hybrid cloud architectures they are joined by standardized or proprietary technologies, enabling orchestration, management, and / or data / application portability across multiple configuration clouds. In this embodiment, both Public Cloud 705 and Private Cloud 706 are part of a larger hybrid cloud.

[0090] One or more embodiments may be systems, methods, apparatus, and / or computer program products at any conceivable level of technical detail of integration. A computer program product may include one or more computer-readable storage media having computer-readable program instructions for causing a processor to carry out aspects of one or more embodiments. A computer-readable storage medium may be a tangible device capable of holding and storing instructions for use by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any preferred combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media may include portable computer diskettes, hard disks, RAM, ROM, erasable programmable read-only memory (EPROM or flash memory), SRAM, portable CD-ROMs, digital multipurpose disks (DVDs), memory sticks, floppy disks, punch cards, or mechanically encoded devices such as grooved raised structures on which instructions are recorded, and any preferred combination of the foregoing. When used herein, computer-readable storage media should not be interpreted as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses passing through fiber optic cables), or electrical signals transmitted through wires.

[0091] The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to each computing / processing device, or to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface within each computing / processing device receives computer-readable program instructions from the network and transfers such computer-readable program instructions for storage in a computer-readable storage medium within each computing / processing device. Computer-readable program instructions for performing the operations of the disclosed subject matter may be assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, configuration data for integrated circuit configuration, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, or similar, and procedural programming languages ​​such as the "C" programming language or similar. Computer-readable program instructions can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or wide area network (WAN), and the connection may be made to an external computer (for example, via the Internet using an Internet service provider).In some embodiments, an electronic circuit configuration, including, for example, a programmable logic circuit configuration, a field-programmable gate array (FPGA), or a programmable logic array (PLA), can be personalized by executing computer-readable program instructions using state information of computer-readable program instructions in order to perform an aspect of the subject matter disclosed.

[0092] In this specification, aspects of the disclosed subject matter are described with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be found that each block in a flowchart and / or block diagram, and combinations of blocks in a flowchart and / or block diagram, can be implemented by computer-readable program instructions. These computer-readable program instructions can be provided to a processor of a general-purpose computer, a dedicated computer, or other programmable data processing device to produce a machine, and as a result, instructions executed through the processor of such computer or other programmable data processing device create a method for implementing one or more blocks of a flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that can instruct a computer, a programmable data processing device, and / or other device to function in a particular manner, and as a result, the computer-readable storage medium storing the instructions contains a product containing instructions that implement the aspects of the functions / actions specified in one or more blocks of a flowchart and / or block diagram. Computer-readable program instructions can also be loaded onto a computer, other programmable data processing device, or other device to execute a series of operations on the computer, other programmable device, or other device, thereby generating a computer implementation process, the instructions executed on the computer, other programmable device, or other device implementing the functions / actions specified in one or more blocks of a flowchart and / or block diagram.

[0093] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the disclosed subject matter. In this context, each block in a flowchart or block diagram may represent a module, segment, or portion of instructions containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions described in a block may occur in a different order than shown in the diagram. For example, two consecutively shown blocks may be executed substantially in parallel, or these blocks may be executed in reverse order depending on the functionality involved. You will also notice that each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, may be implemented by a dedicated hardware-based system that performs a specified function or action, or implements a combination of dedicated hardware and computer instructions.

[0094] While the subject matter has been described above in the general context of computer executable instructions for a computer program product running on one and / or more computers, those skilled in the art will recognize that the disclosure may be implemented in combination with other program modules. Generally, a program module includes routines, programs, components, data structures, etc., that perform a specific task and / or implement a specific abstract data type. Furthermore, those skilled in the art will recognize that the computer implementation methods disclosed herein can be implemented in single-processor or multi-processor computer systems, minicomputing devices, mainframe computers, and other computer system configurations, including computers, handheld computing devices (e.g., PDAs, telephones), microprocessor-based or programmable consumer or industrial electronic devices, and similar devices. The embodiments shown may be implemented in a distributed computing environment where tasks are performed by remote processing devices linked through a communication network. However, some, though not all, embodiments of the disclosure can be implemented in a standalone computer. In a distributed computing environment, program modules can be located in local and remote memory storage devices.

[0095] As used in this application, terms such as “component,” “system,” “platform,” and “interface” may refer to and / or include computer-related entities or entities relating to operating machines having one or more specific functionalities. Entities disclosed herein may be hardware, a combination of hardware and software, software, or running software. For example, a component may, but is not limited to, a process running on a processor, a processor, an object, an executable file, a thread of execution, a program, and / or a computer. As an example, an application running on a server, and both the application and the server, may be components. One or more components may reside in a process and / or thread of execution, and some components may be localized on one computer and / or distributed across two or more computers. In another example, each component may be executed from various computer-readable media storing various data structures. Components can communicate via local and / or remote processes according to signals, etc., which have one or more data packets (for example, data from one component interacting with another component via signals with other systems over a network such as a local system, a distributed system, and / or the Internet). As another example, a component may be a device having inherent functionality provided by mechanical parts operated by an electrical or electronic circuit configuration operated by a software or firmware application executed by a processor. In such a case, the processor may be inside or outside the device and may execute at least part of the software or firmware application.As yet another example, a component may be a device that provides inherent functionality through electronic components without mechanical parts, and the electronic components may include a processor or other method for running software or firmware that at least partially grants the functionality of the electronic components. In one embodiment, a component may emulate electronic components, for example, through a virtual machine in a cloud computing system.

[0096] Furthermore, the term “or” is intended to mean an inclusive “or,” not an exclusive “or.” That is, unless otherwise specified or it is clear from the context, “X adopts A or B” is intended to mean either of the natural inclusive substitutions. That is, “X adopts A or B” is satisfied under any of the aforementioned examples if X adopts A; X adopts B; or X adopts both A and B. Also, the articles “a” and “an” used herein and in accompanying drawings should generally be interpreted as meaning “one or more,” unless otherwise specified or it is clear from the context that they refer to a singular noun. When used herein, the terms “example” and / or “exemplary” are used to mean serving as an example, example, or illustration. To avoid misunderstanding, the subject matter disclosed herein is not limited by such examples. Furthermore, any embodiment or design described herein as “example” and / or “exemplary” should not necessarily be construed as being preferable or advantageous to other embodiments or designs, nor should it be meant to exclude equivalent exemplary structures and techniques known to those skilled in the art.

[0097] The term “processor” as used herein can refer to substantially any computing processing unit or device, including, but is not limited to, single-core processors; single processors with software multithreading capability; multi-core processors; multi-core processors with software multithreading capability; multi-core processors with hardware multithreading technology; parallel platforms; and parallel platforms with distributed shared memory. Additionally, a processor can refer to integrated circuits, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), programmable logic controllers (PLCs), complex-programmable logic devices (CPLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Furthermore, a processor can leverage nanoscale architectures, such as molecular and quantum dot-based transistors, switches, and gates, to optimize space use or enhance the performance of user equipment, but is not limited to these. A processor may be implemented as a combination of computing processing units. In this disclosure, terms such as “memory,” “storage,” “datastore,” “data storage,” “database,” and substantially any other information storage component relating to the operation and functionality of a component are used to refer to “memory” or “memory component” entities embodied in a component containing memory. It should be recognized that the memory and / or memory components described herein may be either volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. By example, and not by limitation, non-volatile memory may include ROM, PROM, EPROM, EEPROM, flash memory, or non-volatile RAM (e.g., FeRAM). Volatile memory may include RAM that can serve as external cache memory, for example.As an example, and not an limitation, RAM is available in many forms, including SRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, DRRAM, DRDRAM, and RDRAM. Additionally, the memory components of computer implementations or systems disclosed herein are intended to include, but are not limited to, these and any other suitable types of memory.

[0098] The above description includes only examples of systems and computer implementations. Naturally, it is impossible to describe every conceivable combination of components or computer implementations for the purpose of illustrating this disclosure, but those skilled in the art will recognize that many further combinations and substitutions of the disclosure are possible. Furthermore, wherever terms such as “includes,” “have,” and “own” are used in the detailed description, claims, appendices, and drawings, such terms are intended to be comprehensive, in the same manner as “equipment” is interpreted when the term “equipment” is adopted as a transitional term in a claim. The descriptions of various embodiments are presented for illustrative purposes and are comprehensive, and are not intended to limit the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein has been selected to best describe the principles of the embodiments, the practical application of the technology found in the market or technical improvements thereto, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A first superconducting quantum interference device (SQUID) coupled between the first and second pads of a first adjustable coupler cubit (TCQ), and a first Josephson junction (JJ) coupled between the second and third pads of the first TCQ; and A second SQUID coupled between the first and second pads of the second TCQ, and a second JJ coupled between the second and third pads of the second TCQ. Equipped with, Here, the second pad of the first TCQ is coupled to the second pad of the second TCQ; the first TCQ is coupled to the first drive line; and the second TCQ is coupled to the second drive line. electronic structure.

2. The electronic structure according to claim 1, wherein the first TCQ is coupled to the second TCQ via direct capacitive coupling.

3. The electronic structure according to claim 1, wherein a coplanar waveguide resonator is coupled between the first TCQ and the second TCQ.

4. The electronic structure according to any of the preceding claims, wherein the first TCQ comprises a first vibrational mode and a second vibrational mode; the second TCQ comprises a third vibrational mode and a fourth vibrational mode; and quantum information can be stored in the first vibrational mode of the first TCQ and the third vibrational mode of the second TCQ.

5. The electronic structure according to any of the preceding claims, wherein the first squid is flux-adjustable via the first drive line, and the second squid is flux-adjustable via the second drive line.

6. The electronic structure according to any of the preceding claims, wherein the first SQUID comprises a first plurality of JJs; the second SQUID comprises a second plurality of JJs; the first sum of critical currents from the first plurality of JJs is substantially the same as the first critical current of the first JJs; and the second sum of critical currents from the second plurality of JJs is substantially the same as the second critical current of the second JJs.

7. The electronic structure according to any one of claims 4 to 6, wherein the second vibration mode of the first TCQ is coupled to the fourth vibration mode of the second TCQ.

8. The electronic structure according to any of the preceding claims, wherein the first TCQ and the second TCQ are capable of performing a controlled phase gate.

9. A first drive line coupled to a first adjustable coupler cubit (TCQ) including a first cubit; and Second driveline coupled to a second adjustable coupler cubit (TCQ) including a second cubit The system comprises, wherein a first magnetic flux is applied to the first TCQ via the first drive line, and a second magnetic flux is applied to the second TCQ via the second drive line, thereby coupling a control phase gate between the first TCQ and the second TCQ. Electronic systems.

10. The electronic system according to claim 9, wherein the first TCQ includes a first vibration mode and a second vibration mode; the second TCQ includes a third vibration mode and a fourth vibration mode; the electronic system is in a first state when the first drive line does not apply the first magnetic flux to the first TCQ and the second drive line does not apply the second magnetic flux to the second TCQ; the electronic system is in a second state when the second magnetic flux is applied to the second TCQ, thereby the frequency of the third vibration mode of the second TCQ is substantially the same as the transition frequency of the first TCQ.

11. The electronic system according to any one of claims 9 to 10, wherein the electronic system is in a third state when the first magnetic flux is applied to the first TCQ and the second magnetic flux is applied to the second TCQ, thereby creating a ZZ interaction between the first TCQ and the second TCQ.

12. The electronic system according to any one of claims 9 to 11, wherein the first TCQ includes a first SQUID coupled between the first pad and the second pad of the first TCQ, and a first JJ coupled between the second pad and the third pad of the first TCQ; and the second TCQ includes a second SQUID coupled between the first pad and the second pad of the second TCQ, and a second JJ coupled between the second pad and the third pad of the second TCQ.

13. The electronic system according to any one of claims 11 to 12, wherein in the first TCQ in the third state, the first vibration mode of the first TCQ and the third vibration mode of the second TCQ each store quantum information.

14. A step of forming a ZZ coupling between a first adjustable coupler cubit (TCQ) and a second adjustable coupler cubit (TCQ) by longitudinally coupling the first TCQ with a first magnetic flux via a first drive line and the second TCQ with a second magnetic flux via a second drive line, wherein the first TCQ and the second TCQ have direct capacitive coupling between the first central pad of the first TCQ and the second central pad of the second TCQ. A method for combining multiple multimode qubits, which include [a specific feature / feature].

15. The method according to claim 14, wherein the first TCQ includes a first vibration mode and a second vibration mode; the second TCQ includes a third vibration mode and a fourth vibration mode; and the second vibration mode of the first TCQ is coupled to the fourth vibration mode of the second TCQ.

16. The method according to claim 15, wherein the first vibration mode of the first TCQ and the third vibration mode of the second TCQ each store quantum information.

17. The method according to any one of claims 15 to 16, further comprising the step of applying a magnetic flux to the first SQUID of the first TCQ via the first drive line to reduce the frequencies of the first vibration mode and the second vibration mode of the first TCQ.

18. The method according to any one of claims 15 to 17, further comprising the step of applying magnetic flux to the first SQUID of the first TCQ via the first drive line to reduce the Josephson energy of the first SQUID and to change the spatial configuration of the first and second vibration modes of the first TCQ.

19. The step of applying the second magnetic flux to the second SQUID of the second TCQ via the second drive line, so that the frequency of the third vibration mode of the second TCQ is substantially the same as the transition frequency of the first TCQ. The method according to any one of claims 15 to 18, further comprising:

20. The method according to any one of claims 14 to 19, wherein a control phase gate is coupled between the first TCQ and the second TCQ.

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