Understanding Loss Mechanisms in InAs-based Gatemon Qubits

Gate tunable Josephson-Junction (JJ) devices on InAs, offer a promising avenue for implementation of voltage-controlled superconducting qubits. Preliminary results demonstrate notable tunability >1GHz in gatemon qubits, however they suffer from a multitude of loss mechanisms. Specific candidates include kinetic inductive losses in the resonators, radiative gate loss, dielectric loss, and junction loss. We present a strategy to quantify various mechanisms that manifest in resonator quality factors. We find that for thin Al, kinetic inductance based losses dominate. For thicker Al, losses are dominated by dielectric loss in the blanket ald layer, and the InP substrate.