Developing Monolithic Superconducting Resonators for Gate-Based Quantum Dot Readout

Gate-based sensing using resonant circuitry has been identified as a promising path towards high fidelity, fast, and compact readout for semiconductor quantum computing architectures. By coupling a quantum dot (QD) system to an LC resonator, the state is inferred via the reflected phase response. The resistive loss in the discrete inductors and loss associated with wirebonds often limit measurement sensitivity. In contrast to oft used surface mount components, we have fabricated Nb superconducting resonators to reduce resistive loss and will explore additional high kinetic inductance materials. The resonators are intended for monolithic integration with QD gates to reduce resonator-gate loss. We present transmission and reflection data used to assess our ability to deterministically fabricate resonators with designed inductance and capacitance values. Efforts to optimize resonance quality factor and integrate resonators with QDs are discussed.