Observation of large many-body Coulomb interaction effects in a doped quantum wire

TL;DR

This study reveals significant many-body Coulomb interaction effects in a doped quantum wire, including large exciton binding energies, a transition to Fermi-edge singularity, and notable band-gap renormalization, highlighting strong 1-D electron interactions.

Contribution

It provides direct experimental evidence of large Coulomb interaction effects in a high-quality doped quantum wire, including exciton binding energy and band-gap renormalization.

Findings

Observation of 2.3 meV charged exciton binding energy

Transition to Fermi-edge singularity at high electron density

Large red-shift in PL due to band-gap renormalization

Abstract

We demonstrate strong one dimensional (1-D) many-body interaction effects in photoluminescence (PL) in a GaAs single quantum wire of unprecedented optical quality, where 1-D electron plasma densities are controlled via electrical gating. We observed PL of 1-D charged excitons with large binding energy of 2.3 meV relative to the neutral excitons, and its evolution to a Fermi-edge singularity at high electron density. Furthermore, we find a strong band-gap renormalization in the 1-D wire, or a large red-shift of PL with increased electron plasma density. Such a large PL red-shift is not observed when we create a high density neutral electron-hole plasma in the same wire, due probably to cancellation of the Coulomb interaction energy in the neutral plasma.