Josephson junction (JJ) structures are disclosed. In some embodiments, a JJ structure may include a non-superconducting structure having a hollow region. A first superconducting structure may be disposed inside the hollow region of the non-superconducting structure, and a second superconducting structure may be disposed around the non-superconducting structure outside the hollow region.

Disclosed herein are quantum dot devices, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a substrate and a quantum well stack disposed on the substrate. The quantum well stack may include a quantum well layer and a back gate, and the back gate may be disposed between the quantum well layer and the substrate.

The subject disclosure is directed towards layered substrate structures with aligned optical access to electrical devices formed thereon for laser processing and electrical device tuning. According to an embodiment, a layered substrate structure is provided that comprises an optical substrate having a first surface and a second surface and a patterned bonding layer formed on the second surface that comprises a bonding region and an open region, wherein the open region exposes a portion of the second surface. The layered substrate structure further comprises a device chip bonded to the patterned bonding layer via the bonding region and comprising at least one electrical component aligned with the optical substrate and the open region. The at least one electrical component can include for example, a thin film wire, an air bridge, a qubit, an electrode, a capacitor or a resonator.

A method of fabricating a semiconductor-superconductor hybrid device comprises providing a workpiece comprising a semiconductor component, a layer of a first superconductor material on the semiconductor component, and a layer of a second superconductor material on the first superconductor material, the second superconductor material being different from the first superconductor material; etching the layer of the second superconductor material to expose a portion of the first superconductor material; and oxidising the portion of the first superconductor material to form a passivating layer on the semiconductor. The first superconductor provides energy coupling between the semiconductor and the second superconductor, and the passivating layer protects the semiconductor while allowing electrostatic access thereto. Also provided are a hybrid device, and a method of etching.

Methods, apparatuses, and devices for Josephson junction preparation includes: obtaining a first pattern structure for generating a first Josephson junction of a first type and a plurality of second pattern structures for generating a plurality of second Josephson junctions of a second type; evaporating a material on the first pattern structure and the plurality of second pattern structures based on a first evaporation direction to generate a first electrode layer for implementing information transmission; forming an insulating layer on the first electrode layer, the insulating layer including a compound corresponding to the material; evaporating the material on the first pattern structure and the plurality of second pattern structures based on a second evaporation direction to generate a second electrode layer for implementing information transmission; and forming the first Josephson junction and the plurality of second Josephson junctions.

The present disclosure provides a superconducting qubit. The superconducting qubit includes: a Josephson junction and a non-Josephson junction area, wherein the non-Josephson junction area includes a first layer of superconducting material, the first layer of superconducting material being superconducting material deposited on the non-Josephson junction area before ion milling on the Josephson junction and the non-Josephson junction area during preparation of the superconducting qubit.

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.

Devices, systems, methods, and/or computer-implemented methods that can facilitate protection of a substrate in a qubit device using sacrificial material are provided. According to an embodiment, a device can comprise a superconducting lead provided on a pillar of a sacrificial material provided on a substrate. The device can further comprise a collapsed superconducting junction provided on the substrate and coupled to the superconducting lead.

A method of fabricating a superconductor device includes providing a first metal layer on top of the substrate. An oxidation of a top surface of the first metal layer is rejected. A second metal layer is deposited on top of the second metal layer. A superconducting alloy of the first metal layer and the second metal layer is created between the first metal layer and the second metal layer. There is no oxide layer between the superconducting alloy and the first metal layer.

Methods, apparatuses, and devices for quantum chip preparation include acquiring a coplanar waveguide in a quantum chip; and establishing a connecting bridge on the coplanar waveguide using a bonding machine, wherein the connecting bridge is configured to connect a first reference ground and a second reference ground located on two sides of the coplanar waveguide to change the chip electromagnetic resonance frequency. A quantum chip includes a transmission line configured for signal transmission; and a resonant cavity coupled to the transmission line and configured to regulate an operating state of qubits on the quantum chip, wherein the transmission line and the resonant cavity are both composed of a coplanar waveguide, the coplanar waveguide is provided with a connecting bridge, and the connecting bridge is configured to connect a first reference ground and a second reference ground on two sides of the coplanar waveguide to change the chip electromagnetic resonance frequency.