Abstract: A superconducting AC switch system includes a switch network configuration comprising a Josephson junction (JJ) coupled to a transmission line having a transmission line impedance, and a magnetic field generator that is configured to switch from inducing a magnetic field in a plane of the JJ, and providing no magnetic field in the plane of the JJ. An AC input signal applied at an input of the switch network configuration is passed through to an output of the switch network configuration in a first magnetic state, and substantially reflected back to the input of the switch network configuration in a second magnetic state. The first magnetic state is one of inducing and not inducing a magnetic field in a plane of the JJ, and the second magnetic state is the other of inducing and not inducing a magnetic field in a plane of the JJ.

Abstract: A superconducting AC switch system includes a switch network configuration comprising a Josephson junction (JJ) coupled to a transmission line having a transmission line impedance, and a magnetic field generator that is configured to switch from inducing a magnetic field in a plane of the JJ, and providing no magnetic field in the plane of the JJ. An AC input signal applied at an input of the switch network configuration is passed through to an output of the switch network configuration in a first magnetic state, and substantially reflected back to the input of the switch network configuration in a second magnetic state. The first magnetic state is one of inducing and not inducing a magnetic field in a plane of the JJ, and the second magnetic state is the other of inducing and not inducing a magnetic field in a plane of the JJ.

Abstract: A method of forming a superconductor structure is disclosed. The method comprises forming a superconductor line in a first dielectric layer, forming a resistor with an end coupled to an end of the superconductor line, and forming a second dielectric layer overlying the resistor. The method further comprises etching a tapered opening through the second dielectric layer to the resistor, and performing a contact material fill with a normal metal material to fill the tapered opening and form a normal metal connector coupled to the resistor.

Abstract: A solid state cooler device is provided that includes a substrate, a first and second conductive pad disposed on the substrate, a first and second superconductor pad each having a side with a plurality of conductive pad contact interfaces spaced apart from one another and being in contact with a surface of respective first and second conductive pads, and a first and second insulating layer disposed between respective first and second superconductor pads, and respective ends of a normal metal layer. A bias voltage is applied between one of a first conductive pad or first superconductor pad and one of the second conductive pad or the second superconductor pad to remove hot electrons from the normal metal layer, and the contact area of the plurality of first and second conductive pad contact interfaces inhibits the transfer of heat back to the first and second superconductor pads.

Abstract: A method of forming a superconductor structure is disclosed. The method comprises forming a superconductor line in a first dielectric layer, forming a resistor with an end coupled to an end of the superconductor line, and forming a second dielectric layer overlying the resistor. The method further comprises etching a tapered opening through the second dielectric layer to the resistor, and performing a contact material fill with a normal metal material to fill the tapered opening and form a normal metal connector coupled to the resistor.

Abstract: One example includes a tunable current element. The element includes a first magnetic flux component that is configured to exhibit a bias flux in response to a first control current. The bias flux can decrease relative energy barriers between discrete energy states of the tunable current element. The element also includes a second magnetic flux component that is configured to exhibit a control flux in response to a second control current. The control flux can change a potential energy of the discrete energy states of the tunable current element to set an energy state of the tunable current element to one of the discrete energy states, such that the magnetic flux component is configured to generate a hysteretic current that provides a magnetic flux at an amplitude corresponding to the energy state of the tunable current element.

Abstract: A solid state cooler device is provided that includes a substrate, a first and second conductive pad disposed on the substrate, a first and second superconductor pad each having a side with a plurality of conductive pad contact interfaces spaced apart from one another and being in contact with a surface of respective first and second conductive pads, and a first and second insulating layer disposed between respective first and second superconductor pads, and respective ends of a normal metal layer. A bias voltage is applied between one of a first conductive pad or first superconductor pad and one of the second conductive pad or the second superconductor pad to remove hot electrons from the normal metal layer, and the contact area of the plurality of first and second conductive pad contact interfaces inhibits the transfer of heat back to the first and second superconductor pads.

Abstract: One example includes a tunable current element. The element includes a first magnetic flux component that is configured to exhibit a bias flux in response to a first control current. The bias flux can decrease relative energy barriers between discrete energy states of the tunable current element. The element also includes a second magnetic flux component that is configured to exhibit a control flux in response to a second control current. The control flux can change a potential energy of the discrete energy states of the tunable current element to set an energy state of the tunable current element to one of the discrete energy states, such that the magnetic flux component is configured to generate a hysteretic current that provides a magnetic flux at an amplitude corresponding to the energy state of the tunable current element.

Abstract: One example includes a magnetic flux source system that includes a tunable current element. The tunable current element includes a SQUID inductively coupled to a first control line that conducts a first control current that induces a bias flux in the SQUID to decrease relative energy barriers between discrete energy states of the tunable current element. The system also includes an inductor in a series loop with the SQUID and inductively coupled to a second control line that conducts a second control current that induces a control flux in the series loop to change a potential energy of the discrete energy states of the tunable current element to set an energy state of the tunable current element to one of the discrete energy states to generate a current that provides a magnetic flux at an amplitude corresponding to the energy state of the at least one tunable current element.

Abstract: One example includes a magnetic flux source system that includes a tunable current element. The tunable current element includes a SQUID inductively coupled to a first control line that conducts a first control current that induces a bias flux in the SQUID to decrease relative energy barriers between discrete energy states of the tunable current element. The system also includes an inductor in a series loop with the SQUID and inductively coupled to a second control line that conducts a second control current that induces a control flux in the series loop to change a potential energy of the discrete energy states of the tunable current element to set an energy state of the tunable current element to one of the discrete energy states to generate a current that provides a magnetic flux at an amplitude corresponding to the energy state of the at least one tunable current element.

Abstract: An integrated circuit is provided that comprises a resistor, a first superconducting structure coupled to a first end of the resistor, and a second superconducting structure coupled to a second end of the resistor. A thermally conductive heat sink structure is coupled to the second end of the resistor for moving hot electrons from the resistor prior to the electrons generating phonons.

Abstract: An integrated circuit is provided that comprises a resistor, a first superconducting structure coupled to a first end of the resistor, and a second superconducting structure coupled to a second end of the resistor. A thermally conductive heat sink structure is coupled to the second end of the resistor for moving hot electrons from the resistor prior to the electrons generating phonons.

Abstract: A microwave circuit is provided that comprises a plurality of transmission lines each configured to receive and propagate a respective waveform signal of a plurality of waveform signals, and a combiner that receives and combines the plurality of waveform signals from outputs of the plurality of transmission lines into a combined output waveform signal that is output terminated by an output termination resistor. The microwave circuit further comprises a compensation signal generator that generates a compensation signal to mitigate reflections associated with the transmission of signals through the microwave circuit.

Abstract: A phase quantum bit is disclosed. In one embodiment, the phase quantum bit may comprise a Josephson junction and a distributed element coupled to the Josephson junction. The distributed element provides a capacitive component and an inductive component of the phase quantum bit.

Abstract: Systems and methods are provided for a tunable transmon qubit. The qubit includes a first Josephson junction on a first path between a transmission line and a circuit ground and second and third Josephson junctions arranged in parallel with one another on a second path between the transmission line and the circuit ground to form a direct current superconducting quantum interference device (DC SQUID). The DC SQUID is in parallel with the first Josephson junction. A capacitor is arranged in parallel with the first Josephson junction and the DC SQUID on a third path between the transmission line and the circuit ground as to form, in combination with the first path, an outer loop of the tunable transmon qubit. A bias circuit is configured to provide a constant bias flux to one of the DC SQUID and the outer loop of the tunable transmon qubit.

Abstract: A microwave circuit is provided that comprises a plurality of transmission lines each configured to receive and propagate a respective waveform signal of a plurality of waveform signals, and a combiner that receives and combines the plurality of waveform signals from outputs of the plurality of transmission lines into a combined output waveform signal that is output terminated by an output termination resistor. The microwave circuit further comprises a compensation signal generator that generates a compensation signal to mitigate reflections associated with the transmission of signals through the microwave circuit.

Abstract: Systems and methods are provided for a tunable transmon qubit. The qubit includes a first Josephson junction on a first path between a transmission line and a circuit ground and second and third Josephson junctions arranged in parallel with one another on a second path between the transmission line and the circuit ground to form a direct current superconducting quantum interference device (DC SQUID). The DC SQUID is in parallel with the first Josephson junction. A capacitor is arranged in parallel with the first Josephson junction and the DC SQUID on a third path between the transmission line and the circuit ground as to form, in combination with the first path, an outer loop of the tunable transmon qubit. A bias circuit is configured to provide a constant bias flux to one of the DC SQUID and the outer loop of the tunable transmon qubit.

Abstract: Systems and methods are provided for improving fidelity of a quantum operation on a quantum bit of interest. A controlled quantum gate operation, controlled by the quantum bit of interest, id performed on an ancillary quantum bit. An energy state of the ancillary quantum bit is measured to facilitate the improvement of the fidelity of the quantum operation.

Abstract: Systems and methods are provided for improving fidelity of a quantum operation on a quantum bit of interest. A controlled quantum gate operation, controlled by the quantum bit of interest, id performed on an ancillary quantum bit. An energy state of the ancillary quantum bit is measured to facilitate the improvement of the fidelity of the quantum operation.

Abstract: High impedance, high frequency nanoscale device electronics configured to interface with low impedance loads include an impedance transforming stage constructed of multiple nanoscale devices, such as carbon nanotube field-effect transistors. In an embodiment of the present invention, an impedance transforming output stage of a multistage amplifier is configured to drive a 50 ohm transmission line with unity voltage gain using multiple carbon nanotube field-effect transistors in parallel. In a further embodiment, a receiver provided for an electronically steered receive array is a monolithic, lumped-element system formed from nanoscale devices and configured to interface with the external electrical systems via a single transmission line.