International Business Machines Corporation

Raytheon Bbn Technologies Corp.

Shwetank Kumar

Matthias Steffen

George Andrew Keefe

Matthew J Farinelli

Mark B Ketchen

Philip C D Hobbs

David P DiVincenzo

Christopher B Lirakis

Richard Lazarus

David DiVincenzo

A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Microwave readout for flux-biased qubits

An apparatus for measuring component performance including a feed line having an input port and an output port, a first resonator connected to the feed line, a first Josephson junction device connected to the first resonator and to ground, and a second resonator connected to the feed line and to ground.

Yield improvement for Josephson junction test device formation

A method for measuring the quantum state of a resonator includes, exciting an input port of a circuit with signal, measuring a phase shift of the signal at an output port of the circuit, wherein the resonator is coupled to the input and the output ports, and calculating a quantum state of the resonator as a function of the measured phase shift of the signal.

Measuring quantum states of superconducting resonators

A hybrid superconductor-optical quantum repeater is provided. The hybrid superconductor-optical quantum repeater comprises an optical subsystem configured to receive an optical signal via an optical channel and a superconductor subsystem coupled to the optical subsystem. The optical subsystem and superconductor subsystem are coupled to one another via a microwave transmission medium. The optical subsystem is configured to receive an optical signal via the optical channel and down-convert a photon of the optical signal to a microwave photon in a microwave output signal that is output to the superconductor subsystem via the microwave transmission medium. The superconductor subsystem stores a quantum state of the microwave photon and transmits the microwave photon along an output channel from the superconductor subsystem.

Hybrid superconductor-optical quantum repeater

Growing community of inventors

White Plains, NY, United States of America

Shwetank Kumar