Chromium-induced ferromagnetism with perpendicular anisotropy in topological crystalline insulator SnTe (111) thin films

Fei Wang, Hongrui Zhang, Jue Jiang, Yi Fan Zhao, Jia Yu, Wei Liu, Da Li, Moses Hung-Wai Chan, Jirong Sun, Zhidong Zhang, Cui Zu Chang

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Topological crystalline insulator is a recently discovered topological phase of matter. It possesses multiple Dirac surface states, which are protected by the crystal symmetry. This is in contrast to the time-reversal symmetry that is operative in the well-known topological insulators. In the presence of a Zeeman field and/or strain, the multiple Dirac surface states are gapped. The high-Chern-number quantum anomalous Hall (QAH) state is predicted to emerge if the chemical potential resides in all the Zeeman gaps. Here, we use molecular-beam epitaxy to grow 12 double-layer (DL) pure and Cr-doped SnTe (111) thin film on heat-Treated SrTiO3 (111) substrate using a quintuple layer of insulating (Bi0.2Sb0.8)2Te3 topological insulator as a buffer film. The Hall traces of Cr-doped SnTe film at low temperatures display square hysteresis loops indicating long-range ferromagnetic order with perpendicular anisotropy. The Curie temperature of the 12DLSn0.9Cr0.1Te film is ∼110 K. Due to the chemical potential crossing the bulk valence bands, the anomalous Hall resistance of 12DLSn0.9Cr0.1Te film is substantially lower than the predicted quantized value (∼1/4h/e2). It is possible that with systematic tuning the chemical potential via chemical doping and electrical gating, the high-Chern-number QAH state can be realized in the Cr-doped SnTe (111) thin film.

Original languageEnglish (US)
Article number115414
JournalPhysical Review B
Volume97
Issue number11
DOIs
StatePublished - Mar 13 2018

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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