A within-chip magnetic field control device is formed in proximity to a Josephson Junction (JJ) structure. The within-chip magnetic field control device includes wiring structures that are located laterally adjacent to the JJ structure. In some embodiments, the magnetic field control device also includes, in addition to the wiring structures, a conductive plate that is connected to the wiring structures and is located beneath the JJ structure. Use of electrical current through the wiring structures induces, either directly or indirectly, a magnetic field into the JJ structure. The strength of the field can be modulated by the amount of current passing through the wiring structures. The magnetic field can be turned off as needed by ceasing to allow current to flow through the wiring structures.

Quantum circuit assemblies that employ active pulse shaping in order to be able to control states of a plurality of qubits with signal pulses propagated over a shared signal propagation channel are disclosed. An example quantum circuit assembly includes a quantum circuit component that includes a first qubit, associated with a first frequency to control the state of the first qubit, and a second qubit, associated with a second frequency to control the state of the second qubit. A shared transmission channel is coupled to the first and second qubits. The assembly further includes a signal pulse generation circuit, configured to generate a signal pulse to be propagated over the shared transmission channel to control the state of the first qubit, where the signal pulse has a center frequency at the first frequency, a bandwidth that includes the second frequency, and a notch at the second frequency.

A method for improving lifetime and coherence time of a qubit in a quantum mechanical device is provided. The method includes providing a substrate having a frontside and a backside, the frontside having at least one qubit formed thereon, the at least one qubit having capacitor pads. The method further includes at least one of removing an amount of substrate material from the backside of the substrate at an area opposite the at least one qubit or depositing a superconducting metal layer at the backside of the substrate at the area opposite the at least one qubit to reduce radiofrequency electrical current loss due to at least one of silicon-air (SA) interface, metal-air (MA) interface or silicon-metal (SM) interface so as to enhance a lifetime (T1) and a coherence time (T2) in the at least one qubit.

A reversible memory element is provided. The reversible memory element comprises a reversible memory cell comprising a Josephson junction and a passive inductor. A ballistic interconnect is connected to the reversible memory cell by a bidirectional input/output port. A polarized input fluxon propagating along the ballistic interconnect exchanges polarity with a stationary stored fluxon in the reversible memory cell in response to the input fluxon reflecting off the reversible memory cell.

A circulator includes a central circuit having a first superconducting island, a second superconducting island, a third superconducting island, and a central island, each in electrical communication with each other via a plurality of Josephson junctions.

One example includes a magnetic Josephson junction (MJJ) system. The system includes a first superconducting material layer and a second superconducting material layer each configured respectively as a galvanic contacts. The system also includes a ferrimagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a fixed net magnetic moment at a predetermined operating temperature of the MJJ system. The system also includes a ferromagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a variable magnetic orientation in response to an applied magnetic field. The MJJ system can be configured to store a binary logical value based on a direction of the variable magnetic orientation of the ferromagnetic material layer. The system further includes a spacer layer arranged between the ferromagnetic and the ferrimagnetic material layers.

Self-powered scale-up toroidal array quantum processing memory device with controllable and adjustable state-switch valves (CASSV) of making and applications at room temperature in a One-Device-Assembly was invented. The devices comprise of multiple layer organo-metallic cross-linked polymers having various superlattice structures based on a double-pole electron-relay in an electron negative and an electron positive manner in the membranes that promoted Cooper pairs coherently transmitting waves within and cross the Josephson toroidal flexible junction barriers at zero-bias. In the One-Device-Assembly system, the CASSV valve provides a delicate balance and enables the whole device system working when an fJ energy consumption was in demand from the quantum qubits; or when an energy storage device stores 1.53 MJ/cm.sup.2 in demand for a routine automobile vehicle without energy dissipation.

Devices, systems, methods, and/or computer-implemented methods that can facilitate a qubit device comprising a vacuum encapsulated Josephson junction are provided. According to an embodiment, a device can comprise a substrate having an encapsulated vacuum cavity provided on the substrate. The device can further comprise one or more superconducting components of a superconducting circuit provided inside the encapsulated vacuum cavity.

A superconducting circuit having a Josephson junction includes a first electrode layer for signal transmission; a second electrode layer for signal transmission; and an insulating layer arranged between the first electrode layer and the second electrode layer to form a Josephson junction, wherein, the first electrode layer and the second electrode layer are composed of a preset material, the insulating layer is composed of a compound corresponding to the preset material, and the preset material includes a non-aluminum superconducting material to prolong a coherence time of superconducting qubits.

Methods, systems and apparatus for forming Josephson junctions with reduced stray inductance. In one aspect, a device includes a substrate; a first superconductor layer on the substrate; an insulator layer on the first superconductor layer; a second superconductor layer on the insulator layer, wherein the first superconductor layer, the insulator layer, and the second superconductor layer form a superconductor tunnel junction; and a third superconductor layer directly on a surface of the first superconductor layer and directly on a surface of the second superconductor layer to provide a first contact to the superconducting tunnel junction and a second contact to the superconductor tunnel junction, respectively.