Conductance in inhomogeneous quantum wires: Luttinger liquid predictions and quantum Monte Carlo results

TL;DR

This paper combines Luttinger liquid theory and quantum Monte Carlo simulations to analyze conductance and local densities in inhomogeneous quantum wires with electron and spin interactions, providing insights into transport properties at junctions.

Contribution

It introduces a combined analytical and numerical approach to study conductance in inhomogeneous quantum wires with both spinless and spinful interactions.

Findings

Luttinger liquid theory accurately predicts conductance behavior near junctions.

Quantum Monte Carlo results validate the theoretical predictions.

Inhomogeneities significantly affect local densities and transport properties.

Abstract

We study electron and spin transport in interacting quantum wires contacted by noninteracting leads. We theoretically model the wire and junctions as an inhomogeneous chain where the parameters at the junction change on the scale of the lattice spacing. We study such systems analytically in the appropriate limits based on Luttinger liquid theory and compare the results to quantum Monte Carlo calculations of the conductances and local densities near the junction. We first consider an inhomogeneous spinless fermion model with a nearest-neighbor interaction and then generalize our results to a spinful model with an onsite Hubbard interaction.