title: Multi-Terminal Spin Valve on Channels with Spin-Momentum Locking.
abstract: It is experimentally established that charge current flowing in a channel with spin-momentum locking such as topological insulator surface states or Rashba interfaces induces a spin voltage, which can be electrically measured with a ferromagnetic contact along the current path. Using this fact in conjunction with Onsager reciprocity arguments, we make the surprising prediction that the anti-parallel resistance of a spin valve can be either larger or smaller than the parallel resistance depending on the direction of spin flow relative to the direction of spin-momentum locking. However, we argue that this remarkable signature of spin-momentum locking can only be observed in multi-terminal measurements. Two-terminal measurements in the linear response regime, will show a single anti-parallel resistance larger than the parallel resistance as commonly observed in channels without spin-orbit coupling. We support this result with detailed numerical calculations based on a semiclassical model that provides insight into the underlying physics.
authors: School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors: Shehrin
authors: S
authors: Sayed
authors: School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors: Seokmin
authors: S
authors: Hong
authors: School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors: Supriyo
authors: S
authors: Datta