Large Unidirectional Magnetoresistance in a Magnetic Topological Insulator.
We report current-direction dependent or unidirectional magnetoresistance (UMR) in magnetic or nonmagnetic topological insulator (TI) heterostructures, Cr_{x}(Bi_{1-y}Sb_{y})_{2-x}Te_{3}/(Bi_{1-y}Sb_{y})_{2}Te_{3}, that is several orders of magnitude larger than in other reported systems. From the magnetic field and temperature dependence, the UMR is identified to originate from the asymmetric scattering of electrons by magnons. In particular, the large magnitude of UMR is an outcome of spin-momentum locking and a small Fermi wave number at the surface of TI. In fact, the UMR is maximized around the Dirac point with the minimal Fermi wave number.
Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.
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Yasuda
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
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Tsukazaki
RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
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Yoshimi
RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
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Takahashi
Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.|RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
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Kawasaki
Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.|RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
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Tokura