International Business Machines Corporation

Juelich Research Center

David P DiVincenzo

Roger Hilsen Koch

George Andrew Keefe

Firat Solgun

Guido Burkard

Dennis Merton Newns

Glenn John Martyna

James Robert Rozen

Chang Chyi Tsuei

Philip C D Hobbs

Shwetank Kumar

Jim Rozen

James R Rozer

Systems, computer-implemented methods, and computer program products to facilitate external port measurement of qubit port responses are provided. According to an embodiment, a computer-implemented method can comprise terminating, by a system operatively coupled to a processor, one or more qubit ports with different electrical connections. The computer-implemented method can also comprise determining, by the system, one or more qubit port responses from external port responses based on the terminating. In some embodiments, the computer-implemented method can further comprise determining, by the system, a multiport admittance function corresponding to at least two of the one or more qubit ports.

External port measurement of qubit port responses

A method (and structure) of coupling a qubit includes locating the qubit near a transmission line approximately at a location corresponding to a node at a predetermined frequency.

Method and structure to isolate a qubit from the environment

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

A qubit (quantum bit) circuit includes a superconducting main loop that is electrically-completed by a serially-interconnected superconducting subloop. The subloop includes two Josephson junctions. A first coil provides a first flux that couples with the main loop but not with the subloop. A second coil provides a second flux that couples with the subloop but not with the main loop.

Gradiometer-based flux qubit for quantum computing and method therefor

Growing community of inventors

Voerendaal, Netherlands

David P DiVincenzo