72 results about "Superconducting circuits" patented technology

This Josephson element has: a first superconducting metal layer comprising a first surface; a second superconducting metal layer comprising a second surface facing the first surface; and an insulating layer provided between the first surface and the second surface, wherein in a plan view seen from a direction orthogonal to the first surface, the contour of the second surface is inside the contour of the first surface.

Systems and methods for transducing and storing qubit signals are provided. The system includes a voltage source, a substrate, and a membrane suspended over the substrate. A phononic crystal oscillator is disposed in a first region of the membrane. The phononic crystal oscillator includes a capacitor having a moving electrode including an array of multiple phononic crystal unit cells. The moving electrode is connected to the voltage source. A superconducting circuit disposed in a second region of the membrane. A plurality of phonon shields and an optical resonator may also be disposed on the membrane.

The application discloses a superconducting circuit preparation method and a quantum chip. The preparation method comprises the following steps: providing a vacuum cavity to accommodate a substrate used for preparing a superconducting circuit; forming an adsorption structure in the interior of the vacuum cavity to adsorb gas impurities in the vacuum cavity; forming a superconducting metal layer on the surface of the substrate; oxidizing the superconducting metal layer to form an oxide film on the surface of the superconducting metal layer; and patterning the superconducting metal layer to obtain the superconducting circuit. The superconducting circuit preparation method provided by the application forms an adsorption structure in the interior of the vacuum cavity before forming the superconducting metal layer on the surface of the substrate, adsorbs residual oxygen, water vapor and other gas impurities in the vacuum cavity by using the adsorption structure, further reduces the content of the gas impurities in the vacuum cavity, greatly reduces the impurity content of the superconducting metal layer formed on the substrate, and effectively guarantees that the prepared superconducting circuit has good electrical performance.

The invention belongs to the technical field of superconducting circuits, and particularly relates to a method and a device for determining current of a signal link coupled to a quantum bit. A shunting device is arranged on the signal link; the method comprises the following steps: acquiring electrical property influence parameters and target electrical property parameters of the shunting device, wherein the electrical property influence parameters comprise unknown sub-parameters of electrical property influence and known structure parameters obtained by measuring the product morphology of the shunting device; constructing a spice model corresponding to the shunting device by using the electrical performance influence parameters, and optimizing the sub-parameters based on the target electrical performance parameters to obtain a spice model with the target electrical performance parameters; and running a signal link comprising the spice model to obtain a current of the signal link coupled to the quantum bit. The method has the advantage that the current value coupled to the bit can be more accurately determined.

Autonomous stabilization of a GKP code by parametric comb modulation of microwave frequencies A microwave-range quantum superconducting circuit includes an energy-tunable Josephson junction element (8) connected to a portion of a linear passive circuit (6) exhibiting several resonant modes, the first-form Foster decomposition of which across the Josephson junction element (8) includes a target resonant mode having an impedance Z greater than 13 kOhms and a pulsation w.The energy of said Josephson junction element (8) is adjustable and modulated by at least two respective pulse trains in which the pulses are separated by a duration of 2π / w and have a width less than one-tenth of this duration, the amplitude of the pulses within each respective pulse train being modulated by a respective sinusoidal carrier and the pulse trains are shifted in pairs respectively by a duration Δt such that |sin(w*Δt)| is 13 kOhms / Z, so that the resonant mode of pulsation w stabilizes in one of two GKP states encoding a qubit. Fig.2.

A superconducting circuit and a quantum computer capable of implementing four-body interaction using a plurality of superconducting qubit circuits supplied with signals of the same frequency are provided. A superconducting circuit (1) includes four superconducting qubit circuits (10), a coupling circuit (20) directly connected to the four superconducting qubit circuits (10). Each of the superconducting qubit circuits (10) indicates a qubit by being in a first phase state or a second phase state, when the number of the superconducting qubit circuits (10) in the first phase state among the four superconducting qubit circuits (10) is an even number, an interaction term of Hamiltonian of the superconducting circuit (1) takes a first value, and when the number of the superconducting qubit circuits (10) in the first phase state among the four superconducting qubit circuits (10) is an odd number, the interaction term takes a second value.

A method to create flexible mutli-conductor cables include fabricating wiring on silicon-on-insulator wafers with lithographic fabrication techniques followed by thinning some sections of the wafer with a silicon etch. Exemplary cables can have fine pitch and low thermal conductivity enabling high density superconducting interconnects between different temperature stages in cryogenic platforms or between superconducting circuits oriented perpendicular to each other. Also presented herein are methods for making and using exemplary cables.

There is provided a system (1) for hosting a bosonic qubit, comprising a non-linear superconducting circuit (3) and a command circuit (5). The non-linear superconducting circuit (3) comprises: at least one resonant portion (9), and an asymmetrically threaded superconducting quantum interference device (ATS) (7) coupled to said at least one resonant portion (9), wherein the ATS (7) comprises a pair of Josephson junctions and an inductive element, wherein the pair of Josephson junctions and the inductor are galvanically connected in parallel such that each of the Josephson junctions respectively forms first and second superconducting loops with the inductive element, wherein the non-linear superconducting circuit has a first physical oscillatory mode for hosting the bosonic qubit, the first physical oscillatory mode having a first resonant frequency. The command circuit (5) comprises a first electromagnetic source (27) configured to thread the first superconducting loop with a first magnetic flux Φ 1 and the second superconducting loop with a second magnetic flux Φ 2 such that the ATS (7) is threaded with a differential flux (formula I) in units of the superconducting flux quantum. The command circuit (5) is further configured to modulate the differential flux (formula II) at a modulation frequency equal to the first resonant frequency ωa.

A superconducting controller for superconducting quantum bits is used for implementing a high-fidelity quantum gate through magnetic flux driving. The controller comprises an inductor which forms an inductance loop and is used for being coupled with a low-mutual-inductance quantum bit inductor; and a pulse shaping circuit for applying a current pulse having a predetermined shape to the inductor. The pulse shaping circuit includes: a superconducting circuit for outputting a single flux quantum (SFQ) pulse; and a digital counting circuit for generating the shape of the current (flux) pulse by controlling the number of SFQ pulses applied to the inductive loop by incrementing or decrementing the current of the inductor by one SFQ pulse at a time.

A write circuit for an MJJ-based memory circuit includes first and second current sources configured to generate first and second currents, respectively. The first current applies an easy axis magnetic field component to an MJJ in a selected memory cell during a write operation. The second current induces a third current through the MJJ in the selected memory cell, the third current being a seed current for setting a π-state current of the MJJ in a superconducting loop in the selected memory cell. The first current source is configured such that, during the write operation, the MJJ cell transitions from i) a π-state, in which current circulates in a clockwise or counterclockwise direction in the superconducting loop, to a zero-state, in which no current circulates in the superconducting loop, and back to the π-state; or ii) from the zero-state to the π-state; or iii) from the π-state to the zero-state.

The various embodiments described herein include methods, devices, and systems for detecting photons. In one aspect, a superconducting circuit includes an optical waveguide and a plurality of superconducting photon detectors optically coupled to the optical waveguide. The superconducting circuit further includes a readout circuit thermally coupled to the plurality of superconducting photon detectors, the readout circuit comprising respective readout components for the plurality of superconducting photon detectors, each respective readout component having a corresponding reset component.

The invention relates to a magnetic coil arrangement (1) having at least one magnetic coil (MS1, MS2, MSN), in particular a stellarator coil or tokamak coil for a nuclear fusion system, wherein: the magnetic coil (MS1, MS2, MSN) comprises a superconducting conductor and one or more annular plate layers which are made of electrically conductive material and in each of which a plurality of windings of the superconducting conductor, which extends along a local longitudinal direction, are accommodated; the windings are arranged in succession in a local transverse direction; and the superconducting conductor of the magnetic coil (MS1, MS2, MSN) is part of a superconducting circuit of the magnetic coil arrangement (1), characterized in that at least one of the plate layers is part of an additional current path (17) which is connected in parallel with respect to at least one portion of the superconducting conductor and, with this, forms a discharge circuit (20), and in that a first switching element (S1) for interrupting the superconducting circuit is present in the superconducting circuit, wherein the switching element (S1) is arranged outside the discharge circuit (20). By means of the magnetic coil arrangement according to the invention, when local heating of the conductor occurs, firstly the magnetic coil can be quickly discharged and secondly the voltage prevailing across the conductor and relative to ground can be limited to an acceptable level.

A superconducting controller for a superconducting qubit to execute high fidelity quantum gates using magnetic flux drive. The controller comprises: an inductance forming an inductive loop and configured to be inductively coupled to a qubit with a small mutual inductance; a pulse shaping circuit configured to apply a current pulse with a predefined shape across the inductance. The pulse shaping circuit comprises: a superconducting circuit configured to output single flux quanta (SFQ) pulses and a digital counter circuit configured to produce the shape of the current (magnetic flux) pulse by controlling the number of SFQ pulses applied to the inductive loop by incrementing or decrementing the current across the inductance by one SFQ pulse at a time.

The application discloses a superconducting circuit and a protection method thereof. The protection method comprises the following steps: providing a substrate on the surface of which a superconducting circuit is formed; and forming a germanium protection layer covering the superconducting circuit on the substrate, so as to reduce or avoid the contact between the surface of the superconducting circuit and the outside world. Since the germanium has high thermal conductivity, good microwave transmission and strong mechanical property, the germanium can not only play an isolation role on the superconducting circuit, but also will not affect the performance of the superconducting circuit, so that the superconducting circuit can be isolated from the outside world without affecting the performance.

A write circuit for writing state into a plurality of superconducting memory cells includes a control circuit, a plurality of write lines, each of the write lines being associated with a corresponding column of the superconducting memory cells and being configured to convey a write column current, and a first plurality of non-superconducting switch devices. Each of the non-superconducting switch devices are integrated with a corresponding one of the write lines and are configured to receive a first control signal supplied by the control circuit for enabling the write column current to flow through the corresponding one of the write lines for writing state into a selected one of the superconducting memory cells associated with the corresponding one of the write lines.

A quantum device includes a chip including a superconducting circuit, a first wiring substrate, a second wiring substrate, first connection portions connecting the chip and a wiring layer on a first surface of the first wiring substrate and second connection portions connecting the second wiring substrate and a wiring layer on a second surface of the first wiring substrate, wherein one or more second connection portions arranged in a first row as viewed from the edge of the first substrate are provided at positions corresponding respectively to one or more of the first connection portions arranged in a first row as viewed from the edge and are arranged closer to the edge than the first connection portions arranged in the first row.

This invention provides a superconducting device that facilitates space-saving, and a method for removing the connector unit. [Solution] The superconducting device comprises a chip having a superconducting circuit, an interposer on which the chip is mounted, a board electrically connected to the interposer, a cooling section to which the board is fixed, a first screw that fixes the board to the cooling section and has a first head with a first screw hole formed therein, and a connector unit that can be fixed to the first screw hole, the connector unit having a second screw hole located in the direction of extension of the first screw hole.

The application provides a quantum storage device, a preparation method and a quantum device, and relates to the technical field of quantum storage devices. The quantum storage device comprises a substrate, a superconducting circuit, at least two support parts, at least two diffusion regions and a superconducting mechanical oscillator. The at least two support parts are arranged vertically on a first surface. The at least two diffusion regions are arranged one by one with the support parts. The at least two diffusion regions are connected with the superconducting mechanical oscillator, so that the superconducting mechanical oscillator is arranged in suspension on the first surface. The superconducting mechanical oscillator comprises a suspension part and at least two cantilever beams, and the cantilever beams are arranged one by one with the diffusion regions. The direction of each cantilever beam is different, so that the at least two cantilever beams jointly form a first branch structure, and the first branch structure is used for reducing the dissipation of vibration energy of the suspension part for the first time based on a dissipative dilution mechanism. The application can guarantee the mechanical stability of the superconducting mechanical oscillator and the preparation yield, and can reduce mechanical loss and improve the quality factor.

Superconducting diodes and methods of operating the same are provided. A superconducting diode includes first and second superconducting portions separated by an asymmetric junction and a transverse electrode coupled to the first superconducting portion. Operating the superconducting diode includes applying a transverse current to the transverse electrode. Techniques described herein may serve as a building block for the continued development of superconducting circuits.

The invention provides a quantum memory device, a preparation method and a quantum device, and relates to the technical field of quantum memory devices. The quantum memory device includes a substrate, a superconducting circuit, at least two support portions, at least two diffusion regions, and a superconducting mechanical oscillator. The at least two supporting parts are vertically arranged on the first surface. The at least two diffusion areas are in one-to-one correspondence with the supporting parts. And the at least two diffusion regions are connected with the superconducting mechanical oscillator, so that the superconducting mechanical oscillator is suspended on the first surface. The superconducting mechanical oscillator comprises a suspension part and at least two cantilever beams, and the cantilever beams and the diffusion areas are arranged in a one-to-one correspondence mode. The orientations of the cantilever beams are different, so that the at least two cantilever beams jointly form a first branch structure, and the first branch structure is used for reducing the dissipation of the vibration energy of the suspended part for the first time based on a dissipation dilution mechanism. According to the invention, the mechanical stability and preparation yield of the superconducting mechanical oscillator can be ensured, the mechanical loss can be reduced, and the quality factor can be improved.

A superconducting controller for a superconducting qubit to execute high fidelity quantum gates using magnetic flux drive. The controller comprises: an inductance forming an inductive loop and configured to be inductively coupled to a qubit with a small mutual inductance; a pulse shaping circuit configured to apply a current pulse with a predefined shape across the inductance. The pulse shaping circuit comprises: a superconducting circuit configured to output single flux quanta (SFQ) pulses and a digital counter circuit configured to produce the shape of the current (magnetic flux) pulse by controlling the number of SFQ pulses applied to the inductive loop by incrementing or decrementing the current across the inductance by one SFQ pulse at a time.

A system and method are provided for determining critical timing paths in a superconducting circuit design including a Josephson junction. An example method includes providing timing information about a plurality of source terminals of at least one logic gate coupled to a first terminal of the at least one logic gate. The method further includes using a processor to determine, based on a first phase assigned to the at least one logic gate and in view of the timing information, whether the first terminal is reachable by a single-throughput quantum SFQ pulse within a predetermined time range.

The nonlinear superconducting quantum circuit includes at least one resonator (30, 32) and a superconducting quantum interferometer (34) with an asymmetric thread galvanically connected to the at least one resonator (30, 32). The nonlinear superconducting circuit has a first mode having a first resonant frequency and a second mode having a second resonant frequency. The ratio between the first resonant frequency and the second resonant frequency is different from 1 / 2. The at least one resonator (30, 32) is configured with inductance and capacitance values ​​whose symbolic representations induce the first and second modes through the superconducting quantum interferometer (34) with an asymmetric thread such that the nonlinear superconducting quantum circuit has a zero-point variation of 0.05 radians or more in the superconducting phase across the superconducting quantum interferometer (34) with an asymmetric thread in the first and second modes.

In some embodiments, a multistate memory cell includes; a storage loop comprising one or more superconducting devices and one or more inductive devices, the storage loop configured to maintain a quantized magnetic field representing a stored state of the multistate memory cell, the stored state from among a set of three or more distinct digital states; and at least three address lines each inductively coupled to the storage loop, wherein, in response to currents applied to the at least three address lines, the inductive couplings of the at least three address lines combine to force the quantized magnetic field to represent a particular one of the three or more distinct digital states.

The application discloses a mask, a manufacturing method thereof, an oblique evaporation plating method and a superconducting circuit. The mask is used for oblique evaporation plating and comprises a first photoresist layer formed on a substrate, wherein the first photoresist layer is formed with a first window exposing the substrate; and a second photoresist layer formed on the first photoresist layer, wherein the second photoresist layer is formed with a second window exposing the first window, and an edge of the first window towards a plating direction exceeds an edge of the second window to form an undercut structure. When the mask is used for plating a superconducting film by oblique evaporation, the sidewall of the first photoresist layer is shielded by the second photoresist layer, so that the film layer is plated only on the sidewall of the second photoresist layer, and the sidewall of the second photoresist layer has a gap with the substrate, so that the film layer on the sidewall of the second photoresist layer is not connected with the film layer on the substrate. When the photoresist is stripped, the film layer on the sidewall of the second photoresist layer is removed together, so that the application can avoid the edge of the superconducting film from being lifted up when the superconducting film is deposited.

The various embodiments described herein include methods, devices, and systems for detecting photons. In one aspect, a superconducting circuit includes an optical waveguide and a plurality of superconducting photon detectors optically coupled to the optical waveguide. The superconducting circuit further includes a readout circuit thermally coupled to the plurality of superconducting photon detectors, the readout circuit comprising respective readout components for the plurality of superconducting photon detectors, each respective readout component having a corresponding reset component.

A superconductor system is provided that includes a superconductor device comprising a plurality of superconductor layers and dielectric layers interleaved with the plurality of superconductor layers, wherein at least one superconductor layer is a ground plane. The superconductor device further includes superconductor circuitry that resides within one or more of the plurality of superconductor layers, and one or more active moats extending through the plurality of superconductor layers and the dielectric layers, wherein at least one flux vortex caused by cryogenic cooling can be removed from at least one of the plurality of superconductor layers into the one or more active moats by the activating and deactivating of the one or more active moats.

A superconducting device includes a chip that has a superconducting circuit, an interposer on which the chip is mounted, a board electrically connected to the interposer, a cooling unit to which the board is fixed, a first screw that fixes the board to the cooling unit and has a first head portion in which a first screw hole is formed, and a connector unit fixable to the first screw hole, in which the connector unit has a second screw hole positioned in an extension direction of the first screw hole with respect to the first screw hole.

The present disclosure relates to methods and systems for generating and stabilising Gottesman–Kitaev-Preskill (GKP) encoded quantum states in a superconducting resonator. A first method enables autonomous correction of phase-flip and bit-flip errors by driving a superconducting resonator with a voltage tone and coupling the resonator to a thermodynamic environment for providing error correction via dissipation of noise-induced entropy. A second method implements a read-out protocol with Josephson junction coupled to an intermediate node of the resonator and driven with an auxiliary voltage tone to distinguish logical GKP states via a measured time-averaged supercurrent. A system comprises a superconducting resonator including a Josephson junction, a voltage source for applying the drive tone, and a coupling to an thermodynamic environment arranged to realise dissipative error correction.

The application discloses an air bridge array, a manufacturing method thereof and a superconducting quantum device, and belongs to the field of superconducting circuits. The method rotates the target element around a first direction perpendicular to the surface of the mask pattern layer, deposits a first plating film material along a second direction, forms a reinforcing film layer on the side of each bridge deck support located in the deposition window, and forms a reinforcing support for the connection of the bridge deck formed by the plating film material on the bridge deck support based on the reinforcing film layer formed by the plating film material in the deposition window, so that the stability of the air bridge can be improved, and collapse caused by insufficient support strength of the bridge pier to the bridge deck can be prevented.