TY - JOUR
T1 - Interplay between interference and Coulomb interaction in the ferromagnetic Anderson model with applied magnetic field
AU - Pedersen, Jonas Nyvold
AU - Bohr, Dan
AU - Wacker, Andreas
AU - Novotný, Tomáš
AU - Schmitteckert, Peter
AU - Flensberg, Karsten
PY - 2009
Y1 - 2009
N2 - We study the competition between interference due to multiple single-particle paths and Coulomb interaction
in a simple model of an Anderson-type impurity with local-magnetic-field-induced level splitting coupled to
ferromagnetic leads. The model along with its potential experimental relevance in the field of spintronics
serves as a nontrivial benchmark system where various quantum-transport approaches can be tested and
compared. We present results for the linear conductance obtained by a spin-dependent implementation of the
density-matrix renormalization-group scheme which are compared with a mean-field solution as well as a
seemingly more advanced Hubbard-I approximation. We explain why mean field yields nearly perfect results
while the more sophisticated Hubbard-I approach fails even at a purely conceptual level since it breaks
hermiticity of the related density matrix. Furthermore, we study finite bias transport through the impurity by
the mean-field approach and recently developed higher-order density-matrix equations. We found that the
mean-field solution fails to describe the plausible results of the higher-order density-matrix approach both
quantitatively and qualitatively, as it does not capture some essential features of the current-voltage characteristics
such as negative differential conductance.
AB - We study the competition between interference due to multiple single-particle paths and Coulomb interaction
in a simple model of an Anderson-type impurity with local-magnetic-field-induced level splitting coupled to
ferromagnetic leads. The model along with its potential experimental relevance in the field of spintronics
serves as a nontrivial benchmark system where various quantum-transport approaches can be tested and
compared. We present results for the linear conductance obtained by a spin-dependent implementation of the
density-matrix renormalization-group scheme which are compared with a mean-field solution as well as a
seemingly more advanced Hubbard-I approximation. We explain why mean field yields nearly perfect results
while the more sophisticated Hubbard-I approach fails even at a purely conceptual level since it breaks
hermiticity of the related density matrix. Furthermore, we study finite bias transport through the impurity by
the mean-field approach and recently developed higher-order density-matrix equations. We found that the
mean-field solution fails to describe the plausible results of the higher-order density-matrix approach both
quantitatively and qualitatively, as it does not capture some essential features of the current-voltage characteristics
such as negative differential conductance.
U2 - 10.1103/PhysRevB.79.125403
DO - 10.1103/PhysRevB.79.125403
M3 - Journal article
SN - 0163-1829
VL - 79
SP - 125403
JO - Physical Review B Condensed Matter
JF - Physical Review B Condensed Matter
ER -