Abstract: An isochronous receiver system is provided and includes a single flux quantum (SFQ) receiver to receive a data signal from a transmission line. The single flux quantum receiver then converts the data signal to an SFQ signal. The system also includes a converter system to convert the SFQ signal to a reciprocal quantum logic (RQL) signal and to phase-align the RQL signal with a sampling phase of an AC clock signal.

Abstract: Systems and methods are provided for applying flux to a quantum-coherent superconducting circuit. In one example, a system includes a long-Josephson junction (LJJ), an inductive loop coupled to the LJJ and inductively coupled to the quantum-coherent superconducting circuit, and a single flux quantum (SFQ) controller configured to apply a SFQ pulse to a first end of the LJJ that propagates the SFQ pulse to a second end of the LJJ, while also applying a flux quantum to the inductive loop resulting in a first value of control flux being applied to the quantum-coherent superconducting circuit.

Abstract: One embodiment describes a memory cell. The memory cell includes a phase hysteretic magnetic Josephson junction (PHMJJ) that is configured to store one of a first binary logic state corresponding to a binary logic-1 state and a second binary logic state corresponding to a binary logic-0 state in response to a write current that is provided to the memory cell and to generate a superconducting phase based on the stored digital state. The memory cell also includes a superconducting read-select device that is configured to implement a read operation in response to a read current that is provided to the memory cell. The memory cell further includes at least one Josephson junction configured to provide an output based on the superconducting phase of the PHMJJ during the read operation, the output corresponding to the stored digital state.

Abstract: One embodiment describes a reciprocal quantum logic (RQL) sense amplifier system. The system includes an input stage configured to amplify a sense current received at an input. The system also includes a detection stage configured to trigger at least one detection Josephson junction (JJ) in response to the amplified sense current and based on a clock signal to generate a single flux quantum (SFQ) pulse. The system further includes a Josephson transmission line (JTL) stage configured to propagate the SFQ pulse to an output of the RQL sense amplifier system based on at least one output JJ and to generate a negative SFQ pulse to reset the at least one detection JJ and the at least one output JJ based on the clock signal.

Abstract: A device including Josephson junctions, and a terminal for receiving a sinusoidal clock signal for providing power to the Josephson junctions, is provided. The device further includes a terminal for receiving an input signal, a clock terminal for receiving a return-to-zero clock signal, and at least one latch. The device also includes at least one logic gate including at least a subset of the Josephson junctions, for processing the input signal and the return-to-zero clock signal to generate a first signal for the at least one latch. Additionally, the device includes at least one phase-mode logic inverter for processing the return-to-zero clock signal to generate a second signal for the at least one latch. The device also includes an output terminal for providing an output of the at least one latch by processing the first signal and the second signal.

Abstract: A device including Josephson junctions, and a terminal for receiving a sinusoidal clock signal for providing power to the Josephson junctions, is provided. The device further includes a terminal for receiving an input signal, a clock terminal for receiving a return-to-zero clock signal, and at least one latch. The device also includes at least one logic gate including at least a subset of the Josephson junctions, for processing the input signal and the return-to-zero clock signal to generate a first signal for the at least one latch. Additionally, the device includes at least one phase-mode logic inverter for processing the return-to-zero clock signal to generate a second signal for the at least one latch. The device also includes an output terminal for providing an output of the at least one latch by processing the first signal and the second signal.

Abstract: One embodiment includes a clock distribution system. The system includes a standing-wave resonator configured to receive and to resonate a sinusoidal clock signal. The standing-wave resonator includes at least one anti-node portion associated with a peak current amplitude of the sinusoidal clock signal. The system also includes at least one clock line interconnecting each of the at least one anti-node portion and an associated circuit. The at least one clock line can be configured to propagate the sinusoidal clock signal for timing functions associated with the associated circuit.

Abstract: One embodiment describes a JMRAM memory cell system. The system includes a phase hysteretic magnetic Josephson junction (PHMJJ) that stores one of a first binary state and a second binary state in response to a write current provided during a data write operation and to provide a superconducting phase based on the stored digital state. The system also includes a directional write element configured to provide a directional bias current during the data write operation to provide the superconducting phase of the PHMJJ in a predetermined direction corresponding to the first binary state. The system further includes at least one Josephson junction having a critical current that is based on the superconducting phase of the PHMJJ and being configured to provide an output corresponding to the stored digital state in response to a read current that is provided during a read operation.

Abstract: One example includes a superconducting circuit. The circuit includes a plurality of layers comprising a first conductor layer and a second conductor layer overlying the first conductor layer, each of the first and second conductor layers comprising at least one signal element. The circuit also includes a ground grid that is conductively coupled to ground and comprises a first plurality of parallel ground lines that occupy the first conductor layer and extend in a first direction and a second plurality of parallel ground lines that occupy the second conductor layer and extend in a second direction that is orthogonal with respect to the first direction.

Abstract: One embodiment includes a superconductive gate system. The superconductive gate system includes a Josephson D-gate circuit comprising a bi-stable loop configured to store a digital state as one of a first data state and a second data state in response to an enable single flux quantum (SFQ) pulse provided on an enable input and a respective presence of or absence of a data SFQ pulse provided on a data input. The digital state can be provided at an output. The readout circuit is coupled to the output and can be configured to reproduce the digital state as an output signal.

Abstract: One embodiment describes a memory cell. The memory cell includes a phase hysteretic magnetic Josephson junction (PHMJJ) that is configured to store one of a first binary logic state corresponding to a binary logic-1 state and a second binary logic state corresponding to a binary logic-0 state in response to a write current that is provided to the memory cell and to generate a superconducting phase based on the stored digital state. The memory cell also includes a superconducting read-select device that is configured to implement a read operation in response to a read current that is provided to the memory cell. The memory cell further includes at least one Josephson junction configured to provide an output based on the superconducting phase of the PHMJJ during the read operation, the output corresponding to the stored digital state.

Abstract: Systems and methods are provided for physical layout of superconductor circuits. The physical layout system and method is configured to place and route the superconducting circuits by first placing the gates in the form of gate tiles within unoccupied areas of a predetermined circuit design based on a netlist. Each gate tile type includes a particular gate type and a plurality of unassigned Josephson junctions that can be employed in the gates and/or the active interconnects. Inductive wires are then routed between gates incorporating and assigning the Josephson junctions to produce active interconnects between the I/O terminals of the gates based on connections defined in the netlist.

Abstract: One example includes a superconducting circuit. The circuit includes a plurality of layers comprising a first conductor layer and a second conductor layer overlying the first conductor layer, each of the first and second conductor layers comprising at least one signal element. The circuit also includes a ground grid that is conductively coupled to ground and comprises a first plurality of parallel ground lines that occupy the first conductor layer and extend in a first direction and a second plurality of parallel ground lines that occupy the second conductor layer and extend in a second direction that is orthogonal with respect to the first direction.

Abstract: One embodiment describes a memory cell. The memory cell includes a phase hysteretic magnetic Josephson junction (PHMJJ) that is configured to store one of a first binary logic state corresponding to a binary logic-1 state and a second binary logic state corresponding to a binary logic-0 state in response to a write current that is provided to the memory cell and to generate a superconducting phase based on the stored digital state. The memory cell also includes a superconducting read-select device that is configured to implement a read operation in response to a read current that is provided to the memory cell. The memory cell further includes at least one Josephson junction configured to provide an output based on the superconducting phase of the PHMJJ during the read operation, the output corresponding to the stored digital state.

Abstract: Systems and methods are provided for physical layout of superconductor circuits. The physical layout system and method is configured to place and route the superconducting circuits by first placing the gates in the form of gate tiles within unoccupied areas of a predetermined circuit design based on a netlist. Each gate tile type includes a particular gate type and a plurality of unassigned Josephson junctions that can be employed in the gates and/or the active interconnects. Inductive wires are then routed between gates incorporating and assigning the Josephson junctions to produce active interconnects between the I/O terminals of the gates based on connections defined in the netlist.

Abstract: One embodiment includes a superconductive gate system. The superconductive gate system includes a Josephson D-gate circuit comprising a bi-stable loop configured to store a digital state as one of a first data state and a second data state in response to an enable single flux quantum (SFQ) pulse provided on an enable input and a respective presence of or absence of a data SFQ pulse provided on a data input. The digital state can be provided at an output. The readout circuit is coupled to the output and can be configured to reproduce the digital state as an output signal.

Abstract: One embodiment describes a memory cell. The memory cell includes a phase hysteretic magnetic Josephson junction (PHMJJ) that is configured to store one of a first binary logic state corresponding to a binary logic-1 state and a second binary logic state corresponding to a binary logic-0 state in response to a write current and to generate a superconducting phase based on the stored digital state. The memory cell also includes at least one Josephson junction having a critical current that is based on the superconducting phase of the PHMJJ and being configured to provide an output corresponding to the stored digital state in response to a read current.

Abstract: One embodiment describes an AC/DC converter system. The system includes a flux-shuttle loop that is inductively coupled with an AC input signal. The system also includes a plurality of Josephson junctions spaced about the flux shuttle loop that are configured to sequentially trigger in response to the AC input signal and to provide a single-flux quantum (SFQ) pulse that moves sequentially around the flux-shuttle loop that results in a DC output signal being provided through an output inductor.

Abstract: Systems and methods are provided for applying flux to a quantum-coherent superconducting circuit. In one example, a system includes a long-Josephson junction (LJJ), an inductive loop coupled to the LJJ and inductively coupled to the quantum-coherent superconducting circuit, and a single flux quantum (SFQ) controller configured to apply a SFQ pulse to a first end of the LJJ that propagates the SFQ pulse to a second end of the LJJ, while also applying a flux quantum to the inductive loop resulting in a first value of control flux being applied to the quantum-coherent superconducting circuit.

Abstract: One aspect of the present invention includes a Josephson magnetic memory system. The system includes a superconducting electrode that conducts a read current. The system also includes a hysteretic magnetic Josephson junction (HMJJ). The HMJJ can store a binary value and convert superconducting pairs associated with the read current flowing through the HMJJ from a singlet-state to a triplet-state. The system further includes a write circuit magnetically coupled to the HMJJ and configured to write the binary value into the at HMJJ in response to at least one write current and a read circuit configured to determine the binary value stored in the HMJJ in response to application of the read current to the HMJJ.