Long-range magnetic order induced surface state in GdBi and DyBi

TL;DR

This study combines ARPES and DFT to reveal new surface states, including a Dirac cone, in GdBi and DyBi, linked to their antiferromagnetic order, differing from other similar compounds.

Contribution

It demonstrates the emergence of unique surface states in GdBi and DyBi due to antiferromagnetic order, expanding understanding of magnetic topological surface states.

Findings

New surface states, including a Dirac cone, appear in AFM GdBi and DyBi.

Surface states are located along different momentum directions than in related compounds.

Electronic structure changes align with AFM-II-A type magnetic order.

Abstract

The recent discovery of unconventional surface-state pairs, which give rise to Fermi arcs and spin textures, in antiferromagnetically ordered rare-earth monopnictides attracted the interest in these materials. We use angle-resolved photoemission spectroscopy (ARPES) measurements in conjunction with density functional theory (DFT) calculations to investigate the evolution of the electronic structure of GdBi and DyBi. We find that new surface states, including a Dirac cone, emerge in the AFM state. However, they are located along a direction in momentum space that is different than what was found in NdSb, NdBi, and CeBi. The observed changes in the electronic structure are consistent with the presence of AFM-II-A type order.