# Correct Brillouin zone and electronic structure of BiPd

## TL;DR

This paper clarifies the correct Brillouin zone of BiPd, demonstrating how previous misidentification affected the understanding of its electronic and topological properties crucial for Majorana fermion research.

## Contribution

It provides a corrected electronic structure analysis of BiPd by properly identifying its Brillouin zone, impacting interpretations of its topological nature.

## Key findings

- Incorrect reciprocal unit cell led to misinterpretation of electronic structure.
- Correct Brillouin zone alters the perceived topological properties.
- Implications for the suitability of BiPd in Majorana fermion applications.

## Abstract

A promising route to the realization of Majorana fermions is in non-centrosymmetric superconductors, in which spin-orbit-coupling lifts the spin degeneracy of both bulk and surface bands. A detailed assessment of the electronic structure is critical to evaluate their suitability for this through establishing the topological properties of the electronic structure. This requires correct identification of the time-reversal-invariant momenta. One such material is BiPd, a recently rediscovered non-centrosymmetric superconductor which can be grown in large, high-quality single crystals and has been studied by several groups using angular resolved photoemission to establish its surface electronic structure. Many of the published electronic structure studies on this material are based on a reciprocal unit cell which is not the actual Brillouin zone of the material. We show here the consequences of this for the electronic structures and show how the inferred topological nature of the material is affected.