Giant Anisotropic Magnetoresistance in a Quantum Anomalous Hall Insulator

Abstract

When a three-dimensional (3D) 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 edge-state transport, distinct from the more extensively studied integer and fractional 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 Cr-doped (Bi,Sb)2Te3 thin films, as the system transitions from a quantum anomalous Hall insulator to a gapless, ferromagnetic topological insulator. The crossover manifests itself in a giant, electrically tunable anisotropic magnetoresistance that we explain using the Landauer-Buttiker formalism. Our methodology provides a powerful means of quantifying edge state contributions to transport in temperature and chemical potential regimes far from perfect quantization.

References in corpus (8)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator
• Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Scale-Invariant Dissipationless Chiral Transport in Magnetic Topological Insulators beyond the Two-Dimensional Limit
• Surface State Magnetization and Chiral Edge States on Topological Insulators
• Interplay between ferromagnetism, surface states, and quantum corrections in a magnetically doped topological insulator

Cited by in corpus (13)

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• Observation of the quantum-anomalous-Hall insulator to Anderson insulator quantum phase transition and its scaling behavior
• Mesoscopic superconductivity and high spin polarization coexisting at metallic point contacts on the Weyl semimetal TaAs
• Chiral transport along magnetic domain walls in the quantum anomalous Hall effect
• Characterizing the Structure of Topological Insulator Thin Films
• Weak Localization and Antilocalization in Topological Materials with Impurity Spin-Orbit Interactions
• Opto-Electronic Characterization of Three Dimensional Topological Insulators
• Observation of superparamagnetism in coexistence with quantum anomalous Hall C=$\pm$1 and C=0 Chern states
• Demonstration of Dissipative Quasihelical Edge Transport in Quantum Anomalous Hall Insulators
• Magnetization governed magnetoresistance anisotropy in topological semimetal CeBi
• Topological antiferromagnetic spintronics: Part of a collection of reviews on antiferromagnetic spintronics
• Interface ferromagnetism and anomalous Hall effect of CdO/ferromagnetic insulator heterostructures