1301.2933 (B. A. Stickler et al.)

Theoretical investigation of room-temperature spin-filtering in
lattice-matched fcc GaAs/CrAs/GaAs heterostructures    [PDF]

B. A. Stickler, C. Ertler, W. Pötz, L. Chioncel

Based on the assumption that thin layers of fcc CrAs can be sandwiched lattice--matched in between GaAs we perform a theoretical study of spin filtering in [1,0,0] GaAs/CrAs/GaAs heterostructures. The electronic structure of fcc GaAs, CrAs, and GaAs/CrAs heterostructures is obtained within LMTO local spin-density functional theory. Relevant segments of the computed band structure are mapped onto an effective nearest--neighbor sp$^3$d$^5$s$^*$ tight-binding model from which, together with the computed band offset, the effective Hamiltonian of the heterostructure is constructed. The current-voltage characteristics are computed within a non-equilibrium Green's function formalism and for several temperatures and thicknesses of the CrAs layer. The results from this investigation indicate that high spin polarization should be feasible with ideal GaAs-CrAs-GaAs heterostructures and persist even at room temperature.

View original: http://arxiv.org/abs/1301.2933