Incipient Formation of an Electron Lattice in a Weakly-Confined Quantum Wire

TL;DR

This study investigates how varying confinement strength and carrier density in GaAs/AlGaAs quantum wires leads to signs of electron lattice formation and complex spin-related states at low temperatures.

Contribution

It provides experimental evidence for the incipient formation of an electron lattice in a weakly-confined quasi-1D quantum wire, revealing conductance jumps and complex magnetic field effects.

Findings

Observation of conductance jump to 4e^2/h indicating double wire formation

Return to 2e^2/h conductance plateau at lower densities

Emergence of complex states under in-plane magnetic field

Abstract

We study the low-temperature transport properties of 1D quantum wires as the confinement strength V_conf and the carrier density n_1D are varied using a combination of split gates and a top gate in GaAs/AlGaAs heterostructures. At intermediate V_conf and n_1D, we observe a jump in conductance to 4e^2/h, suggesting a double wire. On further reducing n_1D, plateau at 2e^2/h returns. Our results show beginnings of the formation of an electron lattice in an interacting quasi-1D quantum wire. In the presence of an in-plane magnetic field, mixing of spin-aligned levels of the two wires gives rise to more complex states.