Voltage-Tunable Coupling to a Coplanar Waveguide Resonator Mediated by a Josephson Junction Field Effect Transistor—Part II

Recent advances and innovation in material systems have provided promising solutions for efficient quantum information processing. Understanding how the properties of such materials affect the functionality and coherence of qubit systems is essential. For superconducting qubit platforms, low-power voltage-controlled Josephson junction field effect transistors (JJ-FET) fabricated on superconductor-semiconductor heterostructures have been utilized to make tunable qubits. Here we present a new voltage-controlled coupler system through coplanar waveguide (CPW) resonators.<br/>Here, we show that a gate-tunable JJ-FET fabricated on an Al-InAs heterostructure embedded in a CPW resonator provides the tunability required to make a tunable coupler. By varying the inductance of the junction using a gate voltage which changes the critical current, properties of the resonator such as its resonance frequency and external quality factor can be tuned. By completely suppressing the supercurrent flowing through the junction, the coupler can provide full isolation. Electromagnetic field simulations are utilized to understand the system’s dynamics.<br/>*This abstract is the second part of a two-part abstract. The first abstract will be presented by William M. Strickland.