Quantum simulation of Fermi-Hubbard models in semiconductor quantum dot arrays

TL;DR

This paper proposes a semiconductor quantum dot array device to simulate Fermi-Hubbard models, enabling exploration of complex quantum phases like Mott insulators and superconductivity with current technology.

Contribution

It introduces a novel device design that allows independent control of interaction parameters and filling, facilitating experimental study of the Hubbard model's phase diagram.

Findings

Potential to observe metal-Mott insulator transition

Feasibility of detecting d-wave superconductivity

Device parameters suitable for current fabrication

Abstract

We propose a device for studying the Fermi-Hubbard model with long-range Coulomb interactions using an array of quantum dots defined in a semiconductor two-dimensional electron gas system. Bands with energies above the lowest energy band are used to form the Hubbard model, which allows for an experimentally simpler realization of the device. We find that depending on average electron density, the system is well described by a one- or two-band Hubbard model. Our device design enables the control of the ratio of the Coulomb interaction to the kinetic energy of the electrons independently to the filling of the quantum dots, such that a large portion of the Hubbard phase diagram may be probed. Estimates of the Hubbard parameters suggest that a metal-Mott insulator quantum phase transition and a d-wave superconducting phase should be observable using current fabrication technologies.