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Published on: January 21, 2016
Tunneling Planar Hall Effect in Topological Insulators: Spin Valves and Amplifiers
Benedikt Scharf1, Alex Matos-Abiague1, Jong E Han1
1Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
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.
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