Abstract: A superconducting integrated circuit may include a magnetic flux transformer having an inner inductive coupling element and an outer inductive coupling element that surrounds the inner inductive coupling element along at least a portion of a length thereof. The magnetic flux transformer may have a coaxial-like geometry such that a mutual inductance between the first inductive coupling element and the second inductive coupling element is sub-linearly proportional to a distance that separates the first inner inductive coupling element from the first outer inductive coupling element. At least one of the first inductive coupling element and the second inductive coupling element may be coupled to a superconducting programmable device, such as a superconducting qubit.

Abstract: A superconducting integrated circuit, comprising a plurality of superconducting circuit elements, each having a variation in operating voltage over time; a common power line; and a plurality of bias circuits, each connected to the common power line, and to a respective superconducting circuit element, wherein each respective bias circuit is superconducting during at least one time portion of the operation of a respective superconducting circuit element, and is configured to supply the variation in operating voltage over time to the respective superconducting circuit element.

Abstract: The present invention provides a superconducting device including a substrate, a first superconducting pattern formed on the substrate, an insulating pattern formed on the first superconducting pattern, and a second superconducting pattern formed at the uppermost level in the multilayered superconducting pattern. A barrier layer of a Josephson junction is formed on the lower side of, or within the second superconducting pattern. The second superconducting pattern constitutes a circuit element on the insulating pattern.

Abstract: A three-terminal device constructed from a Josephson junction with one or more asymmetric control lines is disclosed. The device is constructed with high temperature superconducting materials. The junction can be a bicrystal, SNS (Superconducting-Normal-Superconducting) or any other type of high temperature superconductor junction. The control line is either a conducting or superconducting material which is electrically isolated from the junction but inductively coupled into the junction. A portion of the control line is approximately directly above the junction and has current which at least partially flows parallel or nonparallel to current flowing across the junction. The control line current alters the magnetic field within the junction which changes the critical current of the junction. The junction is in a superconducting or resistive state depending on whether the bias current of the junction is greater than or less than the control current.

Abstract: A sensitive detector and detector system with multi-state element or elements employing the phenomenon of stochastic resonance to enhance signal-to-noise ratio (SNR) and detector sensitivity. Signal output is enhanced by the addition of external noise at the input. A single detector element has these improved outputs. Several stochastic resonance elements may be connected in arrays to further increase SNR of the output, increase detector sensitivity, and linearize the relation between input and output.

Abstract: A physical configuration for a parallel multi-junction superconducting quantum interference device that can be used for a variety of applications involving the detection of magnetic flux, including applications where it is desired to measure the absolute magnitude of the flux. The device of this invention features a novel geometry for a multi-junction interference device which significantly enhances the flux-to-voltage transfer function, thereby yielding a significant improvement in the device sensitivity in its use in a magnetometer, gradiometer, or other applications.

Abstract: Magnetic flux concentrating materials are introduced in superconducting moelectronic devices and circuits as a method and means for fabrication of more compact, higher speed superconducting microelectronic devices and circuits.

Abstract: A superconducting circuit system comprises a biasing circuit for producing a bias current that changes periodically, and a superconducting rectifier circuit driven by the bias current. The superconducting rectifier circuit is supplied with a first pulse train including therein positive and negative pulses in synchronization with the bias current and produces a second pulse train of unipolar pulses in response to a transition of a Josephson junction caused by the pulses of the first pulse train.

Abstract: An electronic clock has a single Josephson junction connected in parallel to a resonant circuit, which is a delay line with a matching resistance at the input end to provide series termination. The opposite end of the delay line is an open end to reflect pulses, and the pulse transit time on the line determines the clock rate. A zero crossing detector is provided to initiate the clock operation when an input signal rises above a given threshold, and a reset circuit is included to turn off the clock when the input signal falls below this threshold. A flip-flop circuit allows the clock to be turned on by alternate initiating signal pulses. A modification includes a pulse rejuvenating circuit at the end of the delay line to offset pulse degradation. All of the circuits are fabricated with Josephson junction elements, and the zero crossing detector, reset circuit, flip-flop circuit and pulse rejuvenator circuits include dc-SQUID's.

Abstract: A switching circuit which comprises a digital circuit formed of a superconductor, a transmission line connected to the digital circuit through magnetic coupling, and a resistor element disposed in the transmission line for differentiating the output of the digital circuit.

Abstract: A DC powered integrated circuit includes a plurality of magnetic flux coupling type Josephson elements. First and second Josephson elements are connected in series to form a first element series circuit of Josephson elements. Third and fourth Josephson elements are connected in series to form a second element series circuit of Josephson elements. The first and second element series circuits are connected in series to form a huffle circuit, with a load inductance, three resistors and a DC current source.

Abstract: An Integrated Superconductor Sampling Oscilloscope may include a sampling gate utilizing superconductor devices such as a Josephson junction device as well as external circuitry for producing a visual representation of an input signal responsive to the output of the sampling gate. The oscilloscope may further comprise an attenuator for receiving the input signal, a trigger recognizer comprising superconductor devices which produces a pulse signal when the input signal from the attenuator exceeds a threshold level, a hold-off gate which produces an output signal when the pulse signal from the trigger recognizer is produced concurrently with a gating event, and electrical variable delay which may comprise superconducting devices and produces a delayed pulse signal in response to an output signal by the hold-off gate and a strobe pulse generator which produces a signal to the sampling gate in response to the pulse signal from the electrical variable delay output.

Abstract: There is provided a quantum flux parametron-type superconducting circuit in which a path with a Josephson device is connected in parallel with exciting inductors of the quantum flux parametron or inductors of exciting line magnetically coupled with the exciting inductors, thereby constructing a phase regulator.

Abstract: A superconducting circuit comprises a quantum flux parametron. In the superconducting circuit, at least one of two Josephson devices is a voltage controlled superconducting device, the critical current of which can be controlled by applying a voltage. By adjusting the applied voltage, the critical currents of the two Josephson devices can be equalized. If an input signal is used as the applied voltage, the input signal can be isolated from an output signal. And further, if both critical currents of the two Josephson devices are increased after an input signal is supplied, the input signal can be stably amplified.

Abstract: This is a superconducting digital logic amplifier for interfacing superconductor circuits with semiconductor circuits. It provides a gigahertz amplifier to convert low voltage superconducting logic signals to higher voltage signals, suitable for semiconductor signal processing circuits. It may, for example, provide a factor of ten voltage gain to raise the 2.5 mV Josephson logic signals of conventional metallic superconductor circuitry to 25 mV signals for input into inexpensive semiconductor amplifiers which, in turn, can power semiconductor logic circuitry. Generally, it utilizes a first series string of Josephson junctions in series with an input Josephson junction to provide a series combination which is then connected in parallel with a second string of higher critical current Josephson junctions. The input signal is introduced between the first series string and the input Josephson junction, and the output terminal is connected at the common connection opposite the input Josephson junction.