title: Giant anisotropic magnetoresistance in a quantum anomalous Hall insulator.
abstract: 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.
authors.affiliation: Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA.
authors.forename: Abhinav
authors.initials: A
authors.lastname: Kandala
authors.affiliation: Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Richardella
authors.affiliation: Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Kempinger
authors.affiliation: Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA.
authors.forename: Chao-Xing
authors.initials: CX
authors.lastname: Liu
authors.affiliation: Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA.
authors.forename: Nitin
authors.identifier: 000000032599346X
authors.initials: N
authors.lastname: Samarth