Raytheon Bbn Technologies Corp.

Hypres, Inc.

Rtx Bbn Technologies, Inc.

Massachusetts Institute of Technology

New York University

Thomas Ohki

Kin Chung Fong

Luke Colin Gene Govia

Oleg A Mukhanov

Hari Kiran Krovi

Alex Kirichenko

Graham Earle Rowlands

Guilhem Jean Ribeill

Andrew David Kent

William D Oliver

Simon Gustavsson

Antti Pekka Vepsalainen

Terry Philip Orlando

Andrew Phillips Wagner

Guilhem Jean Antoine Ribeill

Leonardo Matteo Ranzani

Guilhem Jean Antoi Ribeill

William Daniel Kalfus

Minh-Hai Nguyen

Benjamin Lienhard

Martin Gustafsson

A reservoir computer. In some embodiments, the reservoir computer includes a Duffing oscillator, and a readout circuit, and the readout circuit is configured to calculate a plurality of products, each of the products being calculated by multiplying a sample, of a plurality of samples of a signal from the Duffing oscillator, by a respective weight of a plurality of weights.

Duffing oscillator reservoir computer

Techniques for machine learning assisted qubit state readout are disclosed. A system a set of training data that describes states of multiple qubits, and trains a neural network to determine qubit states based on the set of training data. The system obtains one or more unlabeled qubit signals, and determines one or more states corresponding to the unlabeled qubit signal(s), using the neural network. The unlabeled qubit signal(s) may include one or more multiplexed qubit signals, and the state(s) corresponding to the unlabeled qubit signal(s) may include one or more multi-qubit states based on the multiplexed qubit signal(s).

Machine learning assisted qubit state readout

A reservoir computer. In some embodiments, the reservoir computer includes a series array of Josephson junctions, a coupling impedance, and a readout circuit. In some embodiments, the series array of Josephson junctions includes a plurality of Josephson junctions, connected in series; the coupling impedance is connected in parallel with the series array of Josephson junctions; and the readout circuit is connected to at least three nodes of the series array of Josephson junctions.

Reservoir computer with a series array of Josephson junctions

An amplifier. In some embodiments, the amplifier includes a resonant circuit having a resonant frequency, a pump input, a signal input, and a signal output. The resonant circuit may include a Josephson junction connected to the pump input, the Josephson junction being a superconducting-normal-superconducting junction having two superconducting terminals and being configured to adjust the resonant frequency of the resonant circuit based on a signal received at the pump input.

Josephson parametric amplifier based on superconducting-normal-superconducting junction

A microwave switch. In some embodiments, the microwave switch includes a substrate, a signal conductor, a first ground conductor, on a first side of the signal conductor, and a second ground conductor, on a second side of the signal conductor. The signal conductor, the first ground conductor, and the second ground conductor may be planar conductors on a planar top surface of the substrate. The signal conductor may have a first portion composed of a superconducting material, and a second portion having a reduced cross section, a cross-sectional area of the second portion being less than 120 nm.

Superconducting microwave switch

A transistor. In some embodiments, the transistor includes a first superconducting source-drain, a second superconducting source-drain, a graphene channel including at least a portion of a graphene sheet, and a conductive gate. The first superconducting source-drain, the second superconducting source-drain, and the graphene channel together form a Josephson junction having a critical current. The graphene channel forms a current path between the first superconducting source-drain and the second superconducting source-drain. The conductive gate is configured, upon application of a electric field across the conductive gate and the graphene channel by applying a voltage, to modify the critical current.

Graphene-based superconducting transistor

A photon detector including a graphene-insulating-superconducting junction configured as a temperature sensor. Photons are absorbed by the graphene sheet of the graphene-insulating-superconducting junction, each absorbed photon causing a temporary increase in the temperature of the graphene sheet, and a corresponding change in the differential impedance of the graphene-insulating-superconducting junction. The graphene-insulating-superconducting junction is part of a resonant circuit connected as a shunt load between a radio frequency input transmission line and a radio frequency output transmission line. The transmission S-parameter from input to output is affected by the impedance of the resonant circuit which in turn is affected by the differential impedance of the graphene-insulating-superconducting junction, and therefore by the temperature of the graphene sheet. The absorption of photons is detected by detecting changes in the transmission S-parameter indicating temperature changes caused by the absorption of a photon.

Number-resolving photon detector with graphene-insulating-superconducting junction

A detector for detecting single photons of infrared radiation or longer wavelength electromagnetic radiation. In one embodiment a waveguide configured to transmit infrared radiation is arranged to be adjacent a graphene sheet and configured so that evanescent waves from the waveguide overlap the graphene sheet. In other embodiments a transmission line or antenna is coupled to the graphene sheet and guides longer-wavelength photons to the graphene sheet. A photon absorbed by the graphene sheet heats the graphene sheet. Part of the graphene sheet is part of the Josephson junction as the weak link, and a constant bias current is driven through the Josephson junction; an increase in the temperature of the graphene sheet results in a decrease in the critical current of the Josephson junction and a voltage pulse in the voltage across the Josephson junction. The voltage pulse is detected by the pulse detector.

Josephson junction readout for graphene-based single photon detector

A magnetic random access memory (MRAM) array including: a plurality of MRAM cells arranged in an array configuration, each comprising a first type nTron and a magnetic memory element; a wordline select circuit comprising of a second type nTron to drive a plurality of parallel wordlines; and a plurality of bitline select circuits, each comprising of said second type nTron for writing to and reading from a column of memory cells in the array and each capable of selecting a single MRAM cell for a memory read or write operation, wherein the second nTron has a higher current drive than the first nTron.

Magnetic RAM array architecture

A detector for detecting single photons of infrared radiation. In one embodiment a waveguide configured to transmit infrared radiation is arranged to be adjacent a graphene sheet and configured so that evanescent waves from the waveguide overlap the graphene sheet. In some embodiments the waveguide is omitted and infrared light propagating in free space illuminates the graphene sheet directly. A photon absorbed by the graphene sheet from the evanescent waves heats the graphene sheet. The graphene sheet is coupled to the weak link of a Josephson junction, and a constant bias current is driven through the Josephson junction, so that an increase in the temperature of the graphene sheet results in a decrease in the critical current of the Josephson junction and a voltage pulse in the voltage across the Josephson junction. The voltage pulse is detected by the pulse detector.

A detector for detecting single photons of infrared radiation. In one embodiment a waveguide configured to transmit infrared radiation is arranged to be adjacent a graphene sheet and configured so that evanescent waves from the waveguide overlap the graphene sheet. An infrared photon absorbed by the graphene sheet from the evanescent waves heats the graphene sheet. The graphene sheet is coupled to the weak link of a Josephson junction, and a constant bias current is driven through the Josephson junction, so that an increase in the temperature of the graphene sheet results in a decrease in the critical current of the Josephson junction and a voltage pulse in the voltage across the Josephson junction. The voltage pulse is detected by the pulse detector.

Magnetic ram array architecture

A magnetic memory system includes a superconductor circuit and one or more magnetic memory elements to store data. To write data, a driver circuit in the superconductor circuit generates a magnetic signal for transmission over a superconductor link extending between the superconductor circuit and the magnetic memory element. To read data, a sensing circuit in the superconductor circuit monitors a superconductor link extending from sensing circuit to the magnetic memory element. The magnetic memory element can be a spin-transfer type magnetic memory element.

Growing community of inventors

Arlington, MA, United States of America

Thomas Ohki