Magnetic order in 3D topological insulators-Wishful thinking or gateway to emergent quantumeffects?
Figueroa García, Adriana Isabel (Institut Català de Nanociència i Nanotecnologia)
Hesjedal, Thorsten (University of Oxford. Department of Physics)
Steinke, Nina-Juliane (Institut Laue-Langevin)

Date:	2020
Abstract:	Three-dimensional topological insulators (TIs) are a perfectly tuned quantum-mechanical machinery in which counterpropagating and oppositely spin-polarized conduction channels balance each other on the surface of the material. This topological surface state crosses the bandgap of the TI and lives at the interface between the topological and a trivial material, such as vacuum. Despite its balanced perfection, it is rather useless for any practical applications. Instead, it takes the breaking of time-reversal symmetry (TRS) and the appearance of an exchange gap to unlock hidden quantum states. The quantum anomalous Hall effect, which has first been observed in Cr-doped (Sb,Bi)2Te3, is an example of such a state in which two edge channels are formed at zero field, crossing the magnetic exchange gap. The breaking of TRS can be achieved by magnetic doping of the TI with transition metal or rare earth ions, modulation doping to keep the electronically active channel impurity free, or proximity coupling to a magnetically ordered layer or substrate in heterostructures or superlattices. We review the challenges these approaches are facing in the famous 3D TI (Sb,Bi)2(Se,Te)3 family and try to answer the question whether these materials can live up to the hype surrounding them.
Grants:	European Commission 796925 European Commission 824140 European Commission 899896
Note:	This AIP article is published under license by AIP: https://publishing.aip.org/wp-content/uploads/2019/10/AIPP-Author-License.pdf
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Anomalous hall effects ; Counterpropagating ; Magnetic exchange ; Modulation doping ; Proximity couplings ; Quantum mechanical ; Spin-polarized conduction ; Time reversal symmetries
Published in:	Applied physics letters, Vol. 117, issue 15 (Oct. 2020) , art. 150502, ISSN 1077-3118

DOI: 10.1063/5.0027987

12 p, 3.5 MB

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