A magnetic topological semimetal Sr1-yMn1-zSb2 (y, z< 0.1)

TL;DR

This paper reports a new magnetic semimetal Sr1-yMn1-zSb2 exhibiting relativistic fermion behaviour and ferromagnetism, providing a platform to study the interplay between topological states and spontaneous time-reversal symmetry breaking.

Contribution

It introduces a novel magnetic topological semimetal with unique magnetic and relativistic properties, expanding the understanding of TRS-breaking Weyl semimetals.

Findings

Exhibits nearly massless relativistic fermions with m* = 0.04-0.05 m0.

Displays ferromagnetic order between 304K and 565K.

Shows canted antiferromagnetic order with ferromagnetic component below 304K.

Abstract

Weyl (WSMs) evolve from Dirac semimetals in the presence of broken time-reversal symmetry (TRS) or space-inversion symmetry. The WSM phases in TaAs-class materials and photonic crystals are due to the loss of space-inversion symmetry. For TRS-breaking WSMs, despite numerous theoretical and experimental efforts, few examples have been reported. In this Article, we report a new type of magnetic semimetal Sr1-yMn1-zSb2 (y,z<0.1) with nearly massless relativistic fermion behaviour (m*=0.04-0.05m0, where m0 is the free electron mass). This material exhibits a ferromagnetic order for 304K < T < 565K, but a canted antiferromagnetic order with a ferromagnetic component for T < 304K. The combination of relativistic fermion behaviour and ferromagnetism in Sr1-yMn1-zSb2 offers a rare opportunity to investigate the interplay between relativistic fermions and spontaneous TRS breaking.