Correlation between the bias dependence of tunneling anisotropic magnetoresistance and tunneling magnetoresistance in a La_(0.67)Sr_(0.33)MnO_3-based magnetic tunnel junction

摘要

La_(0.67)Sr_(0.33)MnO_3 (LSMO) is one of the most promising oxide materials for spintronic devices due to its high Curie temperature (T_c〜370 K), colossal magnetoresistance , and its half-metallicity . The band structure of LSMO around the Fermi level E_F, specifically that at the LSMO / SrTiO_3 (STO) tunnel barrier interface, is known to be a complex mixture of the different J-band components, the up-spin eg and t_(2g) states. The t_(2g) states are located at 〜0.5 eV below E_F in the bulk, but are pushed up closer to E_F at the interface . Hence in LSMO, when the carrier energy is tuned between the interfacial e_gand t_(2g) bands, a sharp change of the angular dependence of the density of states (DOS) on the magnetization direction is expected, like in the quantum wells of ferromagnetic semiconductor GaMnAs [4].