Coupling Quantum Dots to 2DEG-Based Superconductor-Semiconductor Hybrids*

We present experimental results for gate-defined lateral quantum dots coupled to a superconductor-semiconductor nanowire based on InAs/Al two-dimensional electron gas (2DEG). We demonstrate independent voltage control of coupling of multiple quantum dots to the superconducting wire on one side and normal semiconducting leads on the other. This provides experimental control of hybridization of discrete dot states to subgap Andreev states in the wire [1,2] and a tool for high-resolution spectroscopy of Andreev states [3], as well as a possibility to use the dots as filters [4]. A high degree of experimental control as well as extension to a variety of device geometries is made possible by the hybrid 2DEG platform.

[1] D. Clarke, Phys. Rev. B 96, 201109(R) (2017)

[2] E. Prada et al, Phys. Rev. B 96, 085418 (2017)

[3] F. Thomas et al, Phys. Rev. B 104, 115415 (2021)

[4] G. Wang, T. Dvir et al, arXiv:2110.05373 (2021)