An active three-terminal superconducting device having an intersection region at which a hot spot may be controllably formed is described. The intersection region may exhibit current crowding in response to imbalances in current densities applied to channels connected to intersection region. The current crowding may form a hot spot, in which the superconducting device may exhibit a measurable resistance. In some cases, a three-terminal superconducting device may be configured to sense an amount of superconducting current flowing in a channel or loop without having to perturb the superconducting state or amount of current flowing in the channel. A three-terminal superconducting device may be used to read out a number of fluxons stored in a superconducting memory element.

A system and method for high-speed, low-power cryogenic computing are presented, comprising ultrafast energy-efficient RSFQ superconducting computing circuits, and hybrid magnetic/superconducting memory arrays and interface circuits, operating together in the same cryogenic environment. An arithmetic logic unit and register file with an ultrafast asynchronous wave-pipelined datapath is also provided. The superconducting circuits may comprise inductive elements fabricated using both a high-inductance layer and a low-inductance layer. The memory cells may comprise superconducting tunnel junctions that incorporate magnetic layers. Alternatively, the memory cells may comprise superconducting spin transfer magnetic devices (such as orthogonal spin transfer and spin-Hall effect devices). Together, these technologies may enable the production of an advanced superconducting computer that operates at clock speeds up to 100 GHz.

A system and method for high-speed, low-power cryogenic computing are presented, comprising ultrafast energy-efficient RSFQ superconducting computing circuits, and hybrid magnetic/superconducting memory arrays and interface circuits, operating together in the same cryogenic environment. An arithmetic logic unit and register file with an ultrafast asynchronous wave-pipelined datapath is also provided. The superconducting circuits may comprise inductive elements fabricated using both a high-inductance layer and a low-inductance layer. The memory cells may comprise superconducting tunnel junctions that incorporate magnetic layers. Alternatively, the memory cells may comprise superconducting spin transfer magnetic devices (such as orthogonal spin transfer and spin-Hall effect devices). Together, these technologies may enable the production of an advanced superconducting computer that operates at clock speeds up to 100 GHz.

A quantum bit array is disclosed. In an embodiment, the quantum bit array includes a control gate coupled to a qubit and at least one pass gate coupled between the qubit and an adjacent qubit to control operation of the qubit of the quantum bit array, a bit line, and a first transistor channel that connects the bit line to the control gate. The array further comprises at least one word line coupled to the first transistor channel. The at least one word line selectively controls charge flow through the first transistor channel. The array further comprises a capacitor coupled to selectively store charge in the first transistor channel.

Systems and methods related to scheduling of tasks for execution in parallel based on geometric reach are described. An example method includes processing information pertaining to connectivity among superconducting components and nodes included in a shared floor plan to generate a plurality of areas of reach, where each of the plurality of areas of reach corresponds to a portion of the shared floor plan. The method further includes generating a plurality of inflated areas of reach by inflating each of the plurality of areas of reach based on a target inductance of wires for routing signals among the superconducting components and the nodes included in the shared floor plan. The method further includes scheduling parallel execution of tasks for routing wires among a subset of the superconducting components and the nodes within any of the plurality of inflated areas of reach satisfying a geometric constraint.

Systems and methods related to scheduling of tasks for execution in parallel based on geometric reach are described. An example method includes processing information pertaining to connectivity among superconducting components and nodes included in a shared floor plan to generate a plurality of areas of reach, where each of the plurality of areas of reach corresponds to a portion of the shared floor plan. The method further includes generating a plurality of inflated areas of reach by inflating each of the plurality of areas of reach based on a target inductance of wires for routing signals among the superconducting components and the nodes included in the shared floor plan. The method further includes scheduling parallel execution of tasks for routing wires among a subset of the superconducting components and the nodes within any of the plurality of inflated areas of reach satisfying a geometric constraint.

The invention describes a memory device which combines a switchable resistive element and a superconductor element electrically in parallel. The switchable resistive element comprises an active material, which is switchable between first and second values of electrical resistivity ρ.sub.1 and ρ.sub.2 at the same temperature, wherein ρ.sub.1 is different to ρ.sub.2. The superconductor element is operable so that at least part of the superconductor element is switchable from a superconducting state to a non-superconducting state. When the superconductor element is switched from the superconducting state to the non-superconducting state, a current injection is provided through the switchable resistive element capable of switching the switchable resistive element between said first and second values of electrical resistivity.

The invention describes a memory device which combines a switchable resistive element and a superconductor element electrically in parallel. The switchable resistive element comprises an active material, which is switchable between first and second values of electrical resistivity ρ.sub.1 and ρ.sub.2 at the same temperature, wherein ρ.sub.1 is different to ρ.sub.2. The superconductor element is operable so that at least part of the superconductor element is switchable from a superconducting state to a non-superconducting state. When the superconductor element is switched from the superconducting state to the non-superconducting state, a current injection is provided through the switchable resistive element capable of switching the switchable resistive element between said first and second values of electrical resistivity.

A transmon qubit comprising a plate capacitor comprising a first plate (202) and a second plate (203) wherein the first plate is disposed opposite to at least a part of the second plate, wherein the first plate and the second plate are connected via a nonlinear inductance element (304), and a capacitance (205) formed between the first plate and the second plate, wherein the first plate and the second plate are configured to form a vacuum gap capacitor.

A transmon qubit comprising a plate capacitor comprising a first plate (202) and a second plate (203) wherein the first plate is disposed opposite to at least a part of the second plate, wherein the first plate and the second plate are connected via a nonlinear inductance element (304), and a capacitance (205) formed between the first plate and the second plate, wherein the first plate and the second plate are configured to form a vacuum gap capacitor.