Reversal of spin polarization in Fe/GaAs (001) driven by resonant surface states: first-principles calculations.
A minority-spin resonant state at the Fe/GaAs(001) interface is predicted to reverse the spin polarization with the voltage bias of electrons transmitted across this interface. Using a Green's function approach within the local spin-density approximation, we calculate the spin-dependent current in a Fe/GaAs/Cu tunnel junction as a function of the applied bias voltage. We find a change in sign of the spin polarization of tunneling electrons with bias voltage due to the interface minority-spin resonance. This result explains recent experimental data on spin injection in Fe/GaAs contacts and on tunneling magnetoresistance in Fe/GaAs/Fe magnetic tunnel junctions.
Chantis
Athanasios N
AN
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. achantis@lanl.gov
Belashchenko
Kirill D
KD
Smith
Darryl L
DL
Tsymbal
Evgeny Y
EY
van Schilfgaarde
Mark
M
Albers
Robert C
RC