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Interplay between different magnetisms in Cr-doped topological insulators.
Xufeng Kou1, Murong Lang, Yabin Fan
1Department of Electrical Engineering, University of California , Los Angeles, California 90095, United States.
ACS Nano
|October 2, 2013
Summary
Magnetic doping of topological insulators breaks time-reversal symmetry, enabling new discoveries. This study shows electric-field control of magnetism in Cr-doped (BixSb1-x)2Te3 thin films, paving the way for spintronics.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Topological insulators (TIs) exhibit unique electronic properties.
- Breaking time-reversal symmetry (TRS) in TIs via magnetic doping leads to exotic phenomena.
- Understanding magnetic interactions in doped TIs is crucial for device applications.
Purpose of the Study:
- To investigate the magneto-transport properties of Cr-doped (BixSb1-x)2Te3 thin films.
- To demonstrate electric-field control over magnetic orders in these materials.
- To explore the interplay between different magnetic coupling mechanisms.
Main Methods:
- Gate-dependent magneto-transport measurements.
- Fabrication of Cr-doped (BixSb1-x)2Te3 thin films.
- Systematic variation of Cr doping concentrations (2% to 20%).
Main Results:
- Demonstrated hole-mediated RKKY coupling and carrier-independent van Vleck magnetism.
- Unveiled the interplay between these two magnetic orders.
- Established methods to enhance or suppress individual magnetic contributions via doping concentration and gate modulation.
Conclusions:
- Electric-field control of ferromagnetism in Cr-doped TIs is achieved.
- These findings are a fundamental step for exploring TRS-breaking TI systems.
- Potential for expanded functionality of TI-based devices in spintronics.
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