# Tuning the Drude weight of Dirac-Weyl fermions in one-dimensional ring traps

## TL;DR

This paper investigates how interactions in a 1D ring of Dirac-Weyl fermions can tune the Drude weight, revealing conditions for its enhancement or suppression, with potential experimental tests in ultracold atom systems.

## Contribution

It demonstrates how asymmetric and symmetric interactions uniquely affect the Drude weight in a 1D Dirac-Weyl fermion system, combining analytical and numerical methods.

## Key findings

- Asymmetric interactions enhance the Drude weight.
- Symmetric interactions suppress the Drude weight.
- Predictions applicable to ultracold fermion experiments.

## Abstract

We study the response to an applied flux of an interacting system of Dirac-Weyl fermions confined in a one-dimensional (1D) ring. Combining analytical calculations with density-matrix renormalization group results, we show that tuning of interactions leads to a unique many-body system that displays either a suppression or an enhancement of the Drude weight - the zero-frequency peak in the ac conductivity - with respect to the non-interacting value. An asymmetry in the interaction strength between same- and different-pseudospin Dirac-Weyl fermions leads to Drude weight enhancement. Viceversa, symmetric interactions lead to Drude weight suppression. Our predictions can be tested in mixtures of ultracold fermions in 1D ring traps.