The anomalous antiferromagnetic topological phase in pressurized SmB6

TL;DR

This paper demonstrates that pressurized SmB6 can host an antiferromagnetic topological phase, revealing unique surface states and potential for spintronics applications, marking the first experimental realization of such a phase.

Contribution

It identifies pressurized SmB6 as the first candidate material exhibiting an antiferromagnetic topological phase and explores its novel surface states and spintronics potential.

Findings

SmB6 becomes an antiferromagnetic topological insulator under pressure

Unique topological surface states arise from antiferromagnetic order

Potential for tunable spin current generation in AFT phase

Abstract

Antiferromagnetic materials, whose time-reversal symmetry is broken, can be classified into the Z2 topology if they respect some specific symmetry. Since the theoretical proposal, however, no materials have been found to host the antiferromagnetic topological (AFT) phase to date. Here, for the first time, we demonstrate that the topological Kondo insulator SmB6 can be an AFT system when pressurized to undergo an antiferromagnetic phase transition. In addition to propose the possible candidate for an AFT material, in this work we also illustrate the anomalous topological surface states of the AFT phase which has not been discussed before. Originating from the interplay between the topological properties and the antiferromagnetic surface magnetization, the topological surface states of the AFT phase behave differently as compared with those of a topological insulator. Besides, the AFT insulators are also found promising in the generation of tunable spin currents, which is an important application in spintronics.