A quantum computing device includes a first chip having a first substrate and one or more qubits disposed on the first substrate. Each of the one or more qubits has an associated resonance frequency. The quantum computing device further includes a second chip having a second substrate and at least one conductive surface disposed on the second substrate opposite the one or more qubits. The at least one conductive surface has at least one dimension configured to adjust the resonance frequency associated with at least one of the one or more qubits to a determined frequency adjustment value.

A superconductor magnetic field effect transistor. The superconductor magnetic field effect transistor may include a sheet of a superconducting material; and a solenoid. The sheet may be substantially flat, and the solenoid may include a plurality of turns, each of the turns being substantially parallel to the sheet. The superconducting material may be a type-II superconducting material.

A method of forming a superconductor structure is disclosed. The method comprises forming a superconductor line in a first dielectric layer, forming a resistor with an end coupled to an end of the superconductor line, and forming a second dielectric layer overlying the resistor. The method further comprises etching a tapered opening through the second dielectric layer to the resistor, and performing a contact material fill with a normal metal material to fill the tapered opening and form a normal metal connector coupled to the resistor.

A hybrid quantum system performs high-fidelity quantum state transduction between a superconducting (SC) microwave qubit and the ground state spin system of a solid-state artificial atom. This transduction is mediated via an acoustic bus connected by piezoelectric transducers to the SC microwave qubit. For SC circuit qubits and diamond silicon vacancy centers in an optimized phononic cavity, the system can achieve quantum state transduction with fidelity exceeding 99% at a MHz-scale bandwidth. By combining the complementary strengths of SC circuit quantum computing and artificial atoms, the hybrid quantum system provides high-fidelity qubit gates with long-lived quantum memory, high-fidelity measurement, large qubit number, reconfigurable qubit connectivity, and high-fidelity state and gate teleportation through optical quantum networks.

Systems and methods for synchronizing operation of control circuits in quantum circuit assemblies are disclosed. An example assembly for controlling operation of a qubit device includes a plurality of control circuits and an event synchronization arrangement. The plurality of control circuits may include a first and a second control circuits, configured to perform, respectively, first and second actions to control operation of the qubit device. The event synchronization arrangement may be used to control operation of the plurality of control circuits to provide to the second control circuit an indication that the first control circuit performed the first action, and to configure the second control circuit to perform the second action in response to receiving the indication that the first control circuit performed the first action. Assemblies disclosed herein provide improved control over qubits, good scalability in the number of qubits included in the device, and/or design flexibility.

Materials with etch selectivity with respect to one another and one or more additional etch-stop layers are used in a Josephson junction structure to allow for integration with a Josephson junction with supporting structures such as resistors. Selective etch processes compatible with high volume manufacturing are used to pattern various layers of the Josephson junction structure to provide a Josephson junction, which is electrically coupled to a support structure.

A quantum computing device is fabricated by forming, on a superconductor layer, a first resist pattern defining a device region and a sensing region within the device region. The superconductor layer within the sensing region is removed, exposing a region of an underlying semiconductor layer outside the device region. The exposed region of the semiconductor layer is implanted, forming an isolation region surrounding the device region. Using an etching process subsequent to the implanting, the sensing region and a portion of the device region of the superconductor layer adjacent to the isolation region are exposed. By depositing a first metal layer within the sensing region, a tunnel junction gate is formed. A reflectrometry wire comprising a second metal within the reflectrometry region is formed. A nanorod contact using the second metal within the portion of the device region outside the sensing region is formed.

Techniques for trapping quasiparticles in superconductor devices are provided. A superconductor device can comprise a substrate layer. The superconductor device can further comprise a first superconductor layer composed of a first superconductor material, on a first surface of a substrate layer. The superconductor device can further comprise a trapping material buried in the first superconductor layer, wherein the trapping material is formulated to trap quasiparticles.

According to one embodiment, an electronic circuit includes a first nonlinear element, a second nonlinear element, and a third nonlinear element. The first nonlinear element includes a first element Josephson junction provided in a first region of a first surface including the first region and a second region. The second nonlinear element includes a second element Josephson junction provided in the second region. The third nonlinear element includes a Josephson junction circuit. At least a part of the Josephson junction circuit is provided on a second surface. The second surface is separated from the first surface in a first direction crossing the first surface. The second surface is along the first surface. The third nonlinear element is configured to be coupled with the first nonlinear element. The third nonlinear element is configured to be coupled with the second nonlinear element.

A stacked quantum computing device including: a first chip including a superconducting qubit, where the superconducting qubit includes a superconducting quantum interference device (SQUID) region, a control region, and a readout region, and a second chip bonded to the first chip, where the second chip includes a first control element overlapping with the SQUID region, a second control element displaced laterally from the control region and without overlapping the control region, and a readout device overlapping the readout region.