Coupling a high-impedance resonator to crystal-phase defined quantum dots in a zincblende InAs nanowire*

Superconducting microwave resonators are commonly used for creating long-range entanglement between superconducting qubits. Only recently, resonators have been coherently coupled to semiconductor spin qubits. However, state of the art architectures rely on an artificial spin-orbit interaction (SOI) introduced by micro magnets. Additionally, electrostatic gates are used for defining double quantum dots (DQDs) that host spin qubits. These requirements complicate device architectures and scale-up.

Here we explore a different approach based on semiconductor nanowires (NWs). NWs posses a large, electrically tunable, intrinsic SOI. As the NW confines charges into one dimension, it is possible to form a well-defined DQD by epitaxially growing crystal-phase defined barriers in the NW. When combined with superconducting resonators, these properties substantially simplify the device architecture and make the semiconductor NWs promising prototypes for a scalable spin-qubit platform. We have realized high-quality, high-impedance, magnetic-field resilient superconducting resonators based on NbTiN and present recent results on coupling these resonators to a crystal-phase defined DQD in a zincblende InAs NW.