Closing a quantum feedback loop inside a cryostat: Autonomous state preparation and long-time memory of a superconducting qubit

Christian Kraglund Andersen, Joseph Kerckhoff, Konrad W. Lehnert +2

We propose to use a cryogenic nonlinear resonator for the projective readout, classical memory, and feedback for a superconducting qubit. This approach sidesteps many of the ineffi…