Exciton Gas Compression and Metallic Condensation in a Single Semiconductor Quantum Wire

TL;DR

This paper investigates the metal-insulator transition in individual semiconductor quantum wires, providing optical evidence of exciton gas compression and metallic liquid condensation at low temperatures, with estimated critical parameters.

Contribution

It presents the first optical evidence of metallic liquid condensation in single quantum wires and characterizes the phase transition parameters in one-dimensional systems.

Findings

Observation of electron-hole liquid behavior in photoluminescence

Spectral features indicating exciton gas compression

Estimated critical density ~1×10^5 cm⁻¹ and temperature ~35 K

Abstract

We study the metal-insulator transition in individual self-assembled quantum wires and report optical evidences of metallic liquid condensation at low temperatures. Firstly, we observe that the temperature and power dependence of the single nanowire photoluminescence follow the evolution expected for an electron-hole liquid in one dimension. Secondly, we find novel spectral features that suggest that in this situation the expanding liquid condensate compresses the exciton gas in real space. Finally, we estimate the critical density and critical temperature of the phase transition diagram at $n_c\sim1\times10^5$ cm$^{-1}$ and $T_c\sim35$ K, respectively.