Physical Review X (Dec 2019)

Topological Electronic Structure and Intrinsic Magnetization in MnBi_{4}Te_{7}: A Bi_{2}Te_{3} Derivative with a Periodic Mn Sublattice

  • Raphael C. Vidal,
  • Alexander Zeugner,
  • Jorge I. Facio,
  • Rajyavardhan Ray,
  • M. Hossein Haghighi,
  • Anja U. B. Wolter,
  • Laura T. Corredor Bohorquez,
  • Federico Caglieris,
  • Simon Moser,
  • Tim Figgemeier,
  • Thiago R. F. Peixoto,
  • Hari Babu Vasili,
  • Manuel Valvidares,
  • Sungwon Jung,
  • Cephise Cacho,
  • Alexey Alfonsov,
  • Kavita Mehlawat,
  • Vladislav Kataev,
  • Christian Hess,
  • Manuel Richter,
  • Bernd Büchner,
  • Jeroen van den Brink,
  • Michael Ruck,
  • Friedrich Reinert,
  • Hendrik Bentmann,
  • Anna Isaeva

DOI
https://doi.org/10.1103/PhysRevX.9.041065
Journal volume & issue
Vol. 9, no. 4
p. 041065

Abstract

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Combinations of nontrivial band topology and long-range magnetic order hold promise for realizations of novel spintronic phenomena, such as the quantum anomalous Hall effect and the topological magnetoelectric effect. Following theoretical advances, material candidates are emerging. Yet, so far a compound that combines a band-inverted electronic structure with an intrinsic net magnetization remains unrealized. MnBi_{2}Te_{4} has been established as the first antiferromagnetic topological insulator and constitutes the progenitor of a modular (Bi_{2}Te_{3})_{n}(MnBi_{2}Te_{4}) series. Here, for n=1, we confirm a nonstoichiometric composition proximate to MnBi_{4}Te_{7}. We establish an antiferromagnetic state below 13 K followed by a state with a net magnetization and ferromagnetic-like hysteresis below 5 K. Angle-resolved photoemission experiments and density-functional calculations reveal a topologically nontrivial surface state on the MnBi_{4}Te_{7}(0001) surface, analogous to the nonmagnetic parent compound Bi_{2}Te_{3}. Our results establish MnBi_{4}Te_{7} as the first band-inverted compound with intrinsic net magnetization providing a versatile platform for the realization of magnetic topological states of matter.