# Finite Drude weight for 1D low temperature conductors

## TL;DR

This paper uses Quantum Monte Carlo methods to study 1D Bose and Fermi systems at finite temperature, showing that superfluidity or Meissner effect vanish at any non-zero temperature, but a finite Drude weight persists in gapless systems.

## Contribution

It provides robust numerical evidence that 1D interacting Bose and Fermi lattice models lack superfluid density or Meissner fraction at any non-zero temperature, challenging previous assumptions.

## Key findings

- No superfluid density for Bosons at non-zero temperature
- No Meissner fraction for Fermions at non-zero temperature
- Finite Drude weight observed in gapless systems

## Abstract

We apply well established finite temperature Quantum Monte Carlo techniques to one dimensional Bose systems with soft and hardcore constraint, as well as to spinless fermion systems. We give clear and robust numerical evidence that, as expected, no superfluid density for Bosons or Meissner fraction for fermions. is possible at {\em any} non zero temperature in one dimensional interacting Bose or fermi lattice models, whereas a finite Drude weight is generally observed in gapless systems, in partial disagreement to previous expectations.