Coulomb drag between quantum wires with different electron densities

TL;DR

This paper investigates how electron-electron interactions cause Coulomb drag between quantum wires with different densities, revealing a transition at low temperatures and suppression effects at high temperatures using the Tomonaga-Luttinger model.

Contribution

It provides a detailed analysis of Coulomb drag behavior in quantum wires with varying densities, including a phase transition and temperature-dependent suppression effects.

Findings

Identification of a commensurate-incommensurate transition at a critical potential difference

Change in drag resistivity dependence on temperature and potential difference

Suppression of Coulomb drag at high temperatures due to density mismatch

Abstract

We study the way back-scattering electron--electron interaction generates Coulomb drag between quantum wires with different densities. At low temperature $T$ the system can undergo a commensurate-- incommensurate transition as the potential difference $|W|$ between the two wires passes a critical value $\Delta$, and this transition is reflected in a marked change in the dependence of drag resistivity on $W$ and $T$. At high temperature a density difference between the wires suppresses Coulomb drag induced by back scattering, and we use the Tomonaga--Luttinger model to study this suppression in detail.