Hybrid metal/semiconductor quantum dots for analog quantum simulation of non-Fermi liquid physics

Few-site semiconductor quantum dot arrays have provided controllable realizations of effective Hamiltonians. However, intersite inhomogeneity presents a major roadblock to scaling and tuning larger arrays. In contrast, the quasi-continuous level spectrum of hybrid metal-semiconductor quantum dots enables the design of arrays of such sites that behave essentially identically while retaining tunability of intersite coupling, providing a platform for simulating strong interactions. Recent work on a pair of hybrid metal/GaAs dots investigated a novel non-Fermi liquid critical point based on Kondo interactions mediated by the charge of the metallic island[1]. The islands had to be a few microns wide, given how ohmic contacts are made to GaAs. The surface Fermi level pinning in InAs provides a pathway for designing submicron hybrid dots with larger charging energy, enabling investigations of critical scaling over a broader temperature range. We have demonstrated the essential ingredients in an InAs quantum well – clean quantum point contacts[2], highly transparent transmission (>99%) of 1D modes into submicron metal islands, and hybrid metal/InAs dots – for building sizable arrays to gain insights into the Kondo lattice coherence in heavy-fermion materials.

1. Pouse, W. et al. arXiv:2108.12691 (2021)

2. Hsueh, C.L., Sriram, P. et al. Phys. Rev. B 105, 195303 (2022)