Many-Body Renormalization of Semiconductor Quantum Wire Excitons: Absorption, Gain, Binding, Unbinding, and Mott Transition

TL;DR

This paper theoretically investigates many-body excitons in GaAs quantum wires, revealing weak density dependence of excitonic peaks and potential for laser operation above the Mott transition density.

Contribution

It introduces a detailed theoretical model using the Bethe-Salpeter equation to analyze excitons in quantum wires, aligning with experimental results and exploring optical gain at high densities.

Findings

Weak carrier density dependence of excitonic peaks up to Mott transition

Observation of optical gain above the Mott transition density

Potential for one-dimensional quantum wire laser operation

Abstract

We consider theoretically the formation and stability of quasi-one dimensional many-body excitons in GaAs quantum wire structures under external photoexcitation conditions by solving the dynamically screened Bethe-Salpeter equation for realistic Coulomb interaction. In agreement with several recent experimental findings the calculated excitonic peak shows very weak carrier density dependence upto (and even above) the Mott transition density, $n_c\sim3\times10^5$ cm$^{-1}$. Above $n_c$ we find considerable optical gain demonstrating compellingly the possibility of one-dimensional quantum wire laser operation.