US 11,790,261 B2
Tunable coupling between a readout cavity and a parametric amplifier to enhance qubit measurements
Eric Rosenthal, Boulder, CO (US); Konrad Lehnert, Boulder, CO (US); and Christian Schneider, Innsbruck (AT)
Assigned to The Regents of the University of Colorado, a body corporate, Denver, CO (US); and Universitat Innsbruck, Innsbruck (AT)
Filed by The Regents of the University of Colorado, a body corporate, Denver, CO (US); and Universitat Innsbruck, Innsbruck (AT)
Filed on Mar. 4, 2021, as Appl. No. 17/192,479.
Claims priority of provisional application 63/062,530, filed on Aug. 7, 2020.
Claims priority of provisional application 62/985,266, filed on Mar. 4, 2020.
Prior Publication US 2022/0164694 A1, May 26, 2022
Int. Cl. G06N 10/40 (2022.01); H03F 19/00 (2006.01)
CPC G06N 10/40 (2022.01) [H03F 19/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for measuring one or more qubits, the method comprising:
sending a signal into a readout cavity to probe a qubit that resides in the readout cavity, resulting in an entangled signal from which to derive a measurement of the qubit;
swapping the entangled signal between the readout cavity and an amplifier device using a tunable coupling between the readout cavity and the amplifier device by connecting a superconducting switch for a duration of time to allow a parametric amplifier in the amplifier device to receive the entangled signal;
amplifying the entangled signal to produce an amplified signal; and
reading out the amplified to a measurement sub-system.