Magnetic quantum phase transition in Cr-doped Bi2 (Sex Te1-x)3 driven by the Stark effect

Zuocheng Zhang, Xiao Feng, Jing Wang, Biao Lian, Jinsong Zhang, Cuizu Chang, Minghua Guo, Yunbo Ou, Yang Feng, Shou Cheng Zhang, Ke He, Xucun Ma, Qi Kun Xue, Yayu Wang

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

The recent experimental observation of the quantum anomalous Hall effect has cast significant attention on magnetic topological insulators. In these magnetic counterparts of conventional topological insulators such as Bi 2 Te 3, a long-range ferromagnetic state can be established by chemical doping with transition-metal elements. However, a much richer electronic phase diagram can emerge and, in the specific case of Cr-doped Bi2 (Sex Te1-x)3, a magnetic quantum phase transition tuned by the actual chemical composition has been reported. From an application-oriented perspective, the relevance of these results hinges on the possibility to manipulate magnetism and electronic band topology by external perturbations such as an electric field generated by gate electrodes - similar to what has been achieved in conventional diluted magnetic semiconductors. Here, we investigate the magneto-transport properties of Cr-doped Bi2 (Sex Te1-x)3 with different compositions under the effect of a gate voltage. The electric field has a negligible effect on magnetic order for all investigated compositions, with the remarkable exception of the sample close to the topological quantum critical point, where the gate voltage reversibly drives a ferromagnetic-to-paramagnetic phase transition. Theoretical calculations show that a perpendicular electric field causes a shift in the electronic energy levels due to the Stark effect, which induces a topological quantum phase transition and, in turn, a magnetic phase transition.

Original languageEnglish (US)
Pages (from-to)953-957
Number of pages5
JournalNature nanotechnology
Volume12
Issue number10
DOIs
StatePublished - Oct 1 2017

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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