title: Tunneling Planar Hall Effect in Topological Insulators: Spin Valves and Amplifiers.
abstract: We investigate tunneling across a single ferromagnetic barrier on the surface of a three-dimensional topological insulator. In the presence of a magnetization component along the bias direction, a tunneling planar Hall conductance (TPHC), transverse to the applied bias, develops. Electrostatic control of the barrier enables a giant Hall angle, with the TPHC exceeding the longitudinal tunneling conductance. By changing the in-plane magnetization direction, it is possible to change the sign of both the longitudinal and transverse differential conductance without opening a gap in the topological surface state. The transport in a topological-insulator-ferromagnet junction can, thus, be drastically altered from a simple spin valve to an amplifier.
authors: Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
authors: Benedikt
authors: B
authors: Scharf
authors: Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
authors: Alex
authors: A
authors: Matos-Abiague
authors: Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
authors: Jong E
authors: JE
authors: Han
authors: Institute for Theoretical Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors: Ewelina M
authors: EM
authors: Hankiewicz
authors: Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
authors: Igor
authors: I
authors: Žutić