Magnetic order induces symmetry breaking in the single-crystalline orthorhombic CuMnAs semimetal

Eve Emmanouilidou, Huibo Cao, Peizhe Tang, Xin Gui, Chaowei Hu, Bing Shen, Junyi Wu, Shou Cheng Zhang, Weiwei Xie, Ni Ni

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Recently, orthorhombic CuMnAs has been proposed to be a magnetic material where topological fermions exist around the Fermi level. Here we report the magnetic structure of the orthorhombic Cu0.95MnAs and Cu0.98Mn0.96As single crystals. While Cu0.95MnAs is a commensurate antiferromagnet below 360 K with a propagation vector of k=0,Cu0.98Mn0.96As undergoes a second-order paramagnetic to incommensurate antiferromagnetic phase transition at 320 K with k=(0.1,0,0), followed by a second-order incommensurate to commensurate antiferromagnetic phase transition at 230 K. In the commensurate antiferromagnetic state, the Mn spins order parallel to the crystallographic b axis but antiparallel to their nearest neighbors, with the spin orientation along the b axis. This magnetic order breaks S2z, the two-fold rotational symmetry around the c axis, resulting in finite band gaps at the crossing point and the disappearance of the massless topological fermions. However, our first-principles calculations suggest that orthorhombic CuMnAs can still host spin-polarized surface states and signature induced by nontrivial topology, which makes it a promising candidate for antiferromagnetic spintronics.

Original languageEnglish (US)
Article number224405
JournalPhysical Review B
Issue number22
StatePublished - Dec 4 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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