2,402 research outputs found
Valley filter in strain engineered graphene
We propose a simple, yet highly efficient and robust device for producing
valley polarized current in graphene. The device comprises of two distinct
components; a region of uniform uniaxial strain, adjacent to an out-of-plane
magnetic barrier configuration formed by patterned ferromagnetic gates. We show
that when the amount of strain, magnetic field strength, and Fermi level are
properly tuned, the output current can be made to consist of only a single
valley contribution. Perfect valley filtering is achievable within
experimentally accessible parameters.Comment: 4 pages, 3 figures; minor corrections, updated Figs. 2 and 3, added
reference
Spin force and intrinsic spin Hall effect in spintronics systems
We investigate the spin Hall effect (SHE) in a wide class of spin-orbit
coupling systems by using spin force picture. We derive the general relation
equation between spin force and spin current and show that the longitudinal
force component can induce a spin Hall current, from which we reproduce the
spin Hall conductivity obtained previously using Kubo's formula. This simple
spin force picture gives a clear and intuitive explanation for SHE
- …