Abstract: A device comprises a first superconducting quantum bit, a second superconducting quantum bit, and a coupler circuit. The first superconducting quantum bit comprises a superconducting tunnel junction and a shunt inductor which form a first superconducting loop. The second superconducting quantum bit comprises a superconducting tunnel junction and a shunt inductor which form a second superconducting loop. The coupler circuit is coupled between the first and second superconducting quantum bits. The coupler circuit is configured to implement an entanglement gate operation between the first and second superconducting quantum bits through exchange interactions between the coupler circuit and the first superconducting quantum bit and the second superconducting quantum bit, when the coupler circuit is driven by a control signal.

Abstract: 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.

Abstract: A system includes a solid state source of THz radiation and a detector. The source of THz radiation may be based on a superconducting material, such as materials containing one or more Josephson junctions (e.g. BSCCO). The source may include a crystal of superconducting material on which a mesa of superconducting material is formed. The resonant coupling between the Josephson oscillations and the fundamental cavity mode of the mesa may lead to synchronization of the Josephson junctions and emission of powerful THz radiation. The mesa may be formed and/or handled such that THz radiation can be emitted by the material without requiring application of an external magnetic field (e.g. the mesa may include a non-uniform compositional gradient, a non-uniform shape, may have radiation non-uniformly applied to the mesa, etc.).

Abstract: A system includes a solid state source of THz radiation and a detector. The source of THz radiation may be based on a superconducting material, such as materials containing one or more Josephson junctions (e.g. BSCCO). The source may include a crystal of superconducting material on which a mesa of superconducting material is formed. The resonant coupling between the Josephson oscillations and the fundamental cavity mode of the mesa may lead to synchronization of the Josephson junctions and emission of powerful THz radiation. The mesa may be formed and/or handled such that THz radiation can be emitted by the material without requiring application of an external magnetic field (e.g. the mesa may include a non-uniform compositional gradient, a non-uniform shape, may have radiation non-uniformly applied to the mesa, etc.).