Long-range electron-electron interactions in quantum dot systems and applications in quantum chemistry

TL;DR

This paper experimentally characterizes long-range electron-electron interactions in quantum dot arrays, demonstrating their significance and potential for simulating quantum chemistry phenomena with a small number of quantum dots.

Contribution

It provides the first detailed experimental measurement of long-range interactions in quantum dot arrays and explores their application in quantum simulation of molecular systems.

Findings

Significant electron interactions up to four sites apart.

Theoretical screening predictions match experimental results.

Ten quantum dots suffice to simulate a hydrogen-like molecule.

Abstract

Long-range interactions play a key role in several phenomena of quantum physics and chemistry. To study these phenomena, analog quantum simulators provide an appealing alternative to classical numerical methods. Gate-defined quantum dots have been established as a platform for quantum simulation, but for those experiments the effect of long-range interactions between the electrons did not play a crucial role. Here we present the first detailed experimental characterization of long-range electron-electron interactions in an array of gate-defined semiconductor quantum dots. We demonstrate significant interaction strength among electrons that are separated by up to four sites, and show that our theoretical prediction of the screening effects matches well the experimental results. Based on these findings, we investigate how long-range interactions in quantum-dot arrays may be utilized for analog simulations of artificial quantum matter. We numerically show that about ten quantum dots are sufficient to observe binding for a one-dimensional $H_2$-like molecule. These combined experimental and theoretical results pave the way for future quantum simulations with quantum dot arrays and benchmarks of numerical methods in quantum chemistry.