# Weak Localization and Antilocalization in Nodal-Line Semimetals: Dimensionality and Topological Effects

## TL;DR

This paper investigates how impurity potential range influences quantum interference effects in nodal-line semimetals, revealing a transition from 3D weak localization to 2D weak antilocalization with distinct magnetoconductivity signatures.

## Contribution

It introduces a theoretical framework connecting impurity scattering range, band topology, and effective dimensionality in quantum corrections to conductivity in nodal-line semimetals.

## Key findings

- Short-range impurities lead to 3D weak localization.
- Long-range impurities induce 2D weak antilocalization.
- Predicted magnetoconductivity signatures include √B and -ln B behaviors.

## Abstract

New materials such as nodal-line semimetals offer a unique setting for novel transport phenomena. Here, we calculate the quantum correction to conductivity in a disordered nodal-line semimetal. The torus-shaped Fermi surface and encircled $\pi$ Berry flux carried by the nodal loop result in a fascinating interplay between the effective dimensionality of electron diffusion and band topology, which depends on the scattering range of the impurity potential relative to the size of the nodal loop. For a short-range impurity potential, backscattering is dominated by the interference paths that do not encircle the nodal loop, yielding a 3D weak localization effect. In contrast, for a long-range impurity potential, the electrons effectively diffuse in various 2D planes and the backscattering is dominated by the interference paths that encircle the nodal loop. The latter, leads to weak antilocalization with a 2D scaling law. Our results are consistent with symmetry consideration, where the two regimes correspond to the orthogonal and symplectic classes, respectively. Furthermore, we present weak-field magnetoconductivity calculations at low temperatures for realistic experimental parameters, and predict that clear scaling signatures $\propto\sqrt{B}$ and $\propto -\ln B$, respectively. The crossover between the 3D weak localization and 2D weak antilocalization can be probed by tuning the Fermi energy, giving a unique transport signature of the nodal-line semimetal.