Superconducting resonators with voltage-controlled frequency and nonlinearity

Voltage-tunable superconductor-semiconductor devices offer a unique platform to realize dynamic tunability in superconducting quantum circuits. By galvanically connecting a gated InAs-Al Josephson junction to a coplanar waveguide resonator, we demonstrate the use of a superconducting element with wideband gate-tunability. We show that the resonant frequency is controlled via a gate-tunable Josephson inductance and that the non-linearity of the InAs-Al junction is non-dissipative as is the case with conventional AlOx-Al junctions. As the gate voltage is decreased, the inductive participation of the junction increases up to 44%, resulting in the resonant frequency being tuned by over 2 GHz. Utilizing the wide tunability of the device, we demonstrate that two resonant modes can be adjusted such that they strongly hybridize, exhibiting an avoided level crossing with a coupling strength of 51 MHz. Implementing such voltage-tunable resonators is the first step toward realizing wafer-scale continuous voltage control in superconducting circuits for qubit-qubit coupling, quantum-limited amplifiers, and quantum memory platforms.