Universal conductance in quantum wires in the presence of Umklapp scattering

TL;DR

This paper demonstrates that in one-dimensional quantum wires, the zero-temperature conductance remains universal at 2e^2/h despite Umklapp scattering, due to renormalization effects from electron-electron interactions and external potential screening.

Contribution

It shows that conductance remains universal in quantum wires with Umklapp scattering when considering external potential screening and chemical potential shifts.

Findings

Conductance is universal at 2e^2/h away from half-filling.

Renormalization effects preserve conductance despite Umklapp scattering.

Results align with recent claims for systems with non-interacting leads.

Abstract

The effects of Umklapp scattering on the zero-temperature conductance in one-dimensional quantum wires are reexamined by taking into account both the screening of external potential and the non-uniform chemical potential shift due to electron-electron interaction. It is shown that in the case away from half-filling the conductance is given by the universal value, $2e^2/h$, even in the presence of Umklapp scattering, owing to these renormalization effects of external potential. The conclusion is in accordance with the recent claim obtained for the system with non-interacting leads being attached to a quantum wire.