Hybrid metal-semiconductor quantum dots in InAs as a platform for quantum simulation

TL;DR

This paper introduces hybrid metal-semiconductor quantum dots in InAs as a scalable platform for quantum simulation, combining uniformity and tunability to explore correlated ground states driven by Coulomb interactions.

Contribution

It reports the fabrication and characterization of hybrid islands with tunable couplings, demonstrating a platform that overcomes limitations of conventional quantum dots.

Findings

Uniform Coulomb peaks in weak-coupling regime

Observation of dynamical Coulomb blockade at higher transmissions

Potential for scalable quantum simulation platforms

Abstract

Arrays of hybrid metal-semiconductor islands offer a new approach to quantum simulation, with key advantages over arrays of conventional quantum dots. Because the metallic component of these hybrid islands has a quasi-continuous level spectrum, each site in an array can be effectively electronically identical; in contrast, each conventional semiconductor quantum dot has its own spectral fingerprint. Meanwhile, the semiconductor component retains gate-tunability of intersite coupling. This combination creates a scalable platform for simulating correlated ground states driven by Coulomb interactions. We report the fabrication and characterization of hybrid metal-semiconductor islands, featuring a submicron metallic component transparently contacting a gate-confined region of an InAs quantum well with tunable couplings to macroscopic leads. Tuning to the weak-coupling limit forms a single-electron transistor with highly-uniform Coulomb peaks, with no resolvable excitation spectrum in the Coulomb diamonds. Upon increasing the transmissions toward the ballistic regime we observe an evolution to dynamical Coulomb blockade.