# Imbert-Fedorov shift in Weyl semimetals: Dependence on monopole charge and intervalley scattering

## TL;DR

This paper investigates how the Imbert-Fedorov shift in Weyl semimetals depends on monopole charge and intervalley scattering, revealing a relation between topological charge and transverse shift, with implications for material characterization.

## Contribution

It extends the understanding of the IF shift to interfaces between Weyl semimetals with arbitrary monopole charges, providing a general relation and experimental insights.

## Key findings

- IF shift proportional to monopole charge for same-charge WSMs
- Derived a general relation between monopole charges and IF shift
- Intervalley scattering leads to qualitatively different IF shift behavior

## Abstract

The Imbert-Fedorov (IF) shift in optics describes the transverse shift of light beams at the reflection interface. Recently, the IF shift of Weyl fermions at the interface between Weyl semimetals (WSMs) with single monopole charge has been studied. Here, we study the IF shift at the interface between two WSMs, each of which is carrying an arbitrary integer monopole charge. We find a general relation between the monopole charges of the two WSMs and the IF shift. In particular, the IF shift is proportional to the monopole charge if both WSMs have the same one. Our results can be used to infer the topology of the materials by experimentally measuring their IF shift. Furthermore, we consider the possibility that the Weyl fermions are scattered to other Weyl cones during the reflection, which results in qualitatively different behavior of the IF shift. While we use a quantum mechanical approach to solve the problem, semiclassical equations of motion and the conservation of total angular momentum can help us intuitively interpret our results in special cases.