Systems and methods for addressing devices in a superconducting circuit

    公开(公告)号:US11879950B2

    公开(公告)日:2024-01-23

    申请号:US17054631

    申请日:2019-05-16

    摘要: Superconducting integrated circuits may advantageously employ superconducting resonators coupled to a microwave transmission line to efficiently address superconducting flux storage devices. In an XY-addressing scheme, a global flux bias may be applied to a number of superconducting flux storage devices via a low-frequency address line, and individual superconducting flux storage devices addressed via application of high-frequency pulses via resonators driven by the microwave transmission line. Frequency multiplexing can be employed to provide signals to two or more resonators. A low-frequency current bias may be combined with a high-frequency current in one or more superconducting resonators to provide Z-addressing. A low-frequency current bias may be combined with a high-frequency current in one or more superconducting resonators to eliminate a flux bias line. A low-frequency current bias may be used at room temperature to identify the presence of a DC short, an open, and/or an unexpected resistance in a superconducting resonator.

    Dynamical isolation of a cryogenic processor

    公开(公告)号:US11561269B2

    公开(公告)日:2023-01-24

    申请号:US17388545

    申请日:2021-07-29

    摘要: A device is dynamically isolated via a broadband switch that includes a plurality of cascade elements in series, wherein each cascade element comprises a first set of SQUIDs in series, a matching capacitor, and a second set of SQUIDs in series. The broadband switch is set to a passing state via flux bias lines during programming and readout of the device and set to a suppression state during device's calculation to reduce operation errors at the device. A device is electrically isolated from high-frequencies via an unbiased broadband switch. A device is coupled to a tunable thermal bath that includes a broadband switch.

    Systems and methods for magnetic shielding for a superconducting computing system

    公开(公告)号:US11064637B2

    公开(公告)日:2021-07-13

    申请号:US16218150

    申请日:2018-12-12

    摘要: A magnetic shielding system that includes a shield that is non-uniform in the axial direction and a shield cap that is non-uniform in the radial direction. Each shield in the system may have a magnetic permeability, thickness, and/or radius that varies in the axial direction to create low-reluctance paths that redirect flux away from a sample towards the ends of the shield. Each shield cap in the system may have a magnetic permeability and/or thickness that varies in the radial direction to create low-reluctance paths that redirect flux away from the sample towards shield walls. An inner shielding layer formed from a material of low permeability and moderate-to-high coercivity may be implemented as the innermost layer of a magnetic shielding system.

    Kinetic inductance for couplers and compact qubits

    公开(公告)号:US12102017B2

    公开(公告)日:2024-09-24

    申请号:US17429456

    申请日:2020-02-13

    摘要: A circuit can include a galvanic coupling of a coupler to a qubit by a segment of kinetic inductance material. The circuit can include a galvanic kinetic inductance coupler having multiple windings. The circuit can include a partially-galvanic coupler having multiple windings. The partially-galvanic coupler can include a magnetic coupling and a galvanic coupling. The circuit can include an asymmetric partially-galvanic coupler having a galvanic coupling and a first magnetic coupling to one qubit and a second magnetic coupling to a second qubit. The circuit can include a compact kinetic inductance qubit having a qubit body loop comprising a kinetic inductance material. A multilayer integrated circuit including a kinetic inductance layer can form a galvanic kinetic inductance coupling. A multilayer integrated circuit including a kinetic inductance layer can form at least a portion of a compact kinetic inductance qubit body loop.

    Method for use with superconducting devices

    公开(公告)号:US11449784B2

    公开(公告)日:2022-09-20

    申请号:US16930512

    申请日:2020-07-16

    摘要: In many cases after degaussing the field distribution in a magnetic material there may be regions within the magnetic material that have ordered domains that contribute a remnant field. There is the need to reduce or eliminate non-uniform fields within a volume of interest left after degaussing a magnetic shield. Degaussing coils surrounding a metal shield can be used to favorably order magnetic domains within the material to counteract the remnant fields left behind following imperfect degaussing. The remnant field value can be measured and a small current may be applied through the degaussing coils. After removing the current, the field can be measured again and a higher current may be applied again through the coils. Repeated applications of currents and field measurement will progressively order domains in the direction of the applied field, resulting in a reduction of the net field and lower field gradient across the volume of interest.

    SUPERCONDUCTING TUNABLE INDUCTANCE

    公开(公告)号:US20210375516A1

    公开(公告)日:2021-12-02

    申请号:US17327230

    申请日:2021-05-21

    IPC分类号: H01F6/06 H01F21/00 H01F41/04

    摘要: A superconducting integrated circuit is fabricated by depositing a ground plane to at least partially overlie a substrate, depositing an insulating layer to at least partially overlie the ground plane, depositing a superconducting layer to at least partially overlie the insulating layer, and forming a superconducting feature in the superconducting layer. An inductance of the superconducting feature is tunable by adjusting a bias current in the ground plane. The ground plane is electrically communicatively coupleable to an electrical ground. Depositing a ground plane includes depositing a first superconducting material to at least partially overlie the substrate and depositing a second superconducting material to at least partially overlie the first superconducting material. A second critical current density of the second superconducting material is higher than a first critical current density of the first superconducting material.

    Dynamical isolation of a cryogenic processor

    公开(公告)号:US11105866B2

    公开(公告)日:2021-08-31

    申请号:US16397790

    申请日:2019-04-29

    摘要: A device is dynamically isolated via a broadband switch that includes a plurality of cascade elements in series, wherein each cascade element comprises a first set of SQUIDs in series, a matching capacitor, and a second set of SQUIDs in series. The broadband switch is set to a passing state via flux bias lines during programming and readout of the device and set to a suppression state during device's calculation to reduce operation errors at the device. A device is electrically isolated from high-frequencies via an unbiased broadband switch. A device is coupled to a tunable thermal bath that includes a broadband switch.

    Systems and devices for filtering electrical signals

    公开(公告)号:US10897068B2

    公开(公告)日:2021-01-19

    申请号:US16134592

    申请日:2018-09-18

    摘要: Adaptions and improvements to coaxial metal powder filters include distributing a dissipative matrix mixture comprising superconductive material, metal powder, epoxy, and/or magnetic material within a volume defined by an outer tubular conductor and inner conductor. The frequency response of the filter may be tuned by exploiting the energy gap frequency of superconductive material in the dissipative matrix. The inner surface of the outer tubular conductor may be covered with a superconductive material. For a dissipative matrix comprising magnetic material or superconductive powder particles of a certain size, an external magnetic field can be applied to tune the frequency response of the filter.