  Symmetry dependent scattering effect by minority interface resonance states
(IRS) has been evidenced in full-epitaxial Fe/MgO/Fe magnetic tunnel junctions
(MTJs). Two types of samples with and without carbon doped bottom Fe/MgO
interface were fabricated to represent two different types of IRS in the
minority channel in the vicinity of the Fermi level. By analysis of the first-
principles calculated local density of states (LDOS) and the temperature
dependence of conductance in parallel configuration at low bias, we show that
the IRS in the carbon free sample is dominated by the delta5 symmetry. This has
a major contribution on the majority deltai to delta5 channel scattering and
explains the enhancement of the delta5 conductance in the parallel
configuration at low temperature. Furthermore, the spectral composition of the
IRS in the carbon doped interface is found to be dominated by the delta1
symmetry, which is responsible for the suppression of delta5 channel in the
parallel conductance.
