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Title: Theoretical investigation of spin-filtering in CrAs/GaAs heterostructures

The electronic structure of bulk zinc-blende GaAs, zinc-blende and tetragonal CrAs, and CrAs/GaAs supercells, computed within linear muffin-tin orbital (LMTO) local spin-density functional theory, is used to extract the band alignment for the [1,0,0] GaAs/CrAs interface in dependence of the spin orientation. With the lateral lattice constant fixed to the experimental bulk GaAs value, a local energy minimum is found for a tetragonal CrAs unit cell with a longitudinal ([1,0,0]) lattice constant reduced by ≈2%. Due to the identified spin-dependent band alignment, half-metallicity of CrAs no longer is a key requirement for spin-filtering. Based on these findings, we study the spin-dependent tunneling current in [1,0,0] GaAs/CrAs/GaAs heterostructures within the non-equilibrium Green's function approach for an effective tight-binding Hamiltonian derived from the LMTO electronic structure. Results indicate that these heterostructures are promising candidates for efficient room-temperature all-semiconductor spin-filtering devices.
Authors:
; ;  [1] ;  [2]
  1. Institute of Physics, Karl-Franzens Universität Graz, Graz (Austria)
  2. Institute of Physics, Theoretical Physics III, Center for Electronic Correlations and Magnetism, University of Augsburg, D-86135 Augsburg (Germany)
Publication Date:
OSTI Identifier:
22266173
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALIGNMENT; DENSITY FUNCTIONAL METHOD; ELECTRONIC STRUCTURE; GALLIUM ARSENIDES; GREEN FUNCTION; HAMILTONIANS; LATTICE PARAMETERS; MUFFIN-TIN POTENTIAL; SEMICONDUCTOR MATERIALS; SPIN; SPIN ORIENTATION; TUNNEL EFFECT; ZINC SULFIDES