TY - JOUR
T1 - Giant anisotropic magnetoresistance in a quantum anomalous Hall insulator
AU - Kandala, Abhinav
AU - Richardella, Anthony
AU - Kempinger, Susan
AU - Liu, Chao Xing
AU - Samarth, Nitin
N1 - Funding Information:
We acknowledge support from DARPA MESO (Grant No. N66001-11-1-4110), ONR (Grant No. N00014-12-1-0117) and ARO MURI (Grant No. W911NF-12-1-0461), as well as use of the NSF National Nanofabrication Users Network Facility at Penn State. We thank N.P. Ong, Minhao Liu and J. Jain for useful discussions.
Publisher Copyright:
© 2015 Macmillan Publishers Limited. All rights reserved.
PY - 2015/7/7
Y1 - 2015/7/7
N2 - When a three-dimensional ferromagnetic topological insulator thin film is magnetized out-of-plane, conduction ideally occurs through dissipationless, one-dimensional (1D) chiral states that are characterized by a quantized, zero-field Hall conductance. The recent realization of this phenomenon, the quantum anomalous Hall effect, provides a conceptually new platform for studies of 1D transport, distinct from the traditionally studied quantum Hall effects that arise from Landau level formation. An important question arises in this context: how do these 1D edge states evolve as the magnetization is changed from out-of-plane to in-plane? We examine this question by studying the field-tilt-driven crossover from predominantly edge-state transport to diffusive transport in Crx(Bi,Sb)2-x Te3 thin films. This crossover manifests itself in a giant, electrically tunable anisotropic magnetoresistance that we explain by employing a Landauer-Büttiker formalism. Our methodology provides a powerful means of quantifying dissipative effects in temperature and chemical potential regimes far from perfect quantization.
AB - When a three-dimensional ferromagnetic topological insulator thin film is magnetized out-of-plane, conduction ideally occurs through dissipationless, one-dimensional (1D) chiral states that are characterized by a quantized, zero-field Hall conductance. The recent realization of this phenomenon, the quantum anomalous Hall effect, provides a conceptually new platform for studies of 1D transport, distinct from the traditionally studied quantum Hall effects that arise from Landau level formation. An important question arises in this context: how do these 1D edge states evolve as the magnetization is changed from out-of-plane to in-plane? We examine this question by studying the field-tilt-driven crossover from predominantly edge-state transport to diffusive transport in Crx(Bi,Sb)2-x Te3 thin films. This crossover manifests itself in a giant, electrically tunable anisotropic magnetoresistance that we explain by employing a Landauer-Büttiker formalism. Our methodology provides a powerful means of quantifying dissipative effects in temperature and chemical potential regimes far from perfect quantization.
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U2 - 10.1038/ncomms8434
DO - 10.1038/ncomms8434
M3 - Article
AN - SCOPUS:84936804891
SN - 2041-1723
VL - 6
JO - Nature communications
JF - Nature communications
M1 - 7434
ER -