Observation of Interfacial Antiferromagnetic Coupling between Magnetic Topological Insulator and Antiferromagnetic Insulator

Fei Wang, Di Xiao, Wei Yuan, Jue Jiang, Yi Fan Zhao, Ling Zhang, Yunyan Yao, Wei Liu, Zhidong Zhang, Chaoxing Liu, Jing Shi, Wei Han, Moses H.W. Chan, Nitin Samarth, Cui Zu Chang

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Inducing magnetic orders in a topological insulator (TI) to break its time reversal symmetry has been predicted to reveal many exotic topological quantum phenomena. The manipulation of magnetic orders in a TI layer can play a key role in harnessing these quantum phenomena toward technological applications. Here we fabricated a thin magnetic TI film on an antiferromagnetic (AFM) insulator Cr 2 O 3 layer and found that the magnetic moments of the magnetic TI layer and the surface spins of the Cr 2 O 3 layers favor interfacial AFM coupling. Field cooling studies show a crossover from negative to positive exchange bias clarifying the competition between the interfacial AFM coupling energy and the Zeeman energy in the AFM insulator layer. The interfacial exchange coupling also enhances the Curie temperature of the magnetic TI layer. The unique interfacial AFM alignment in magnetic TI on AFM insulator heterostructures opens a new route toward manipulating the interplay between topological states and magnetic orders in spin-engineered heterostructures, facilitating the exploration of proof-of-concept TI-based spintronic and electronic devices with multifunctionality and low power consumption.

Original languageEnglish (US)
Pages (from-to)2945-2952
Number of pages8
JournalNano letters
Volume19
Issue number5
DOIs
StatePublished - May 8 2019

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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