Broadband superconducting switches for integrated quantum networks

Switching elements are a generally useful tool in superconducting circuit experiments. They may be used to reconfigure the connectivity of a network, multiplex qubit readout, and create non-reciprocal devices. In particular, broadband switches allow for the construction of a broadband, on-chip microwave circulator. For integration with superconducting qubits, however, these switches must be low-loss and dissipate negligible heat when switching. Engineering such switches requires reactive circuit elements that tune rapidly between low and high impedance. To achieve these effects, we develop widely tunable SQUID arrays and present measurements of their performance. We then describe a new generation of broadband superconducting switches.