TY - JOUR

T1 - Anderson impurity model at finite Coulomb interaction U

T2 - Generalized noncrossing approximation

AU - Kroha, J.

AU - Haule, K.

AU - Wölfle, P.

AU - Kirchner, S.

PY - 2001

Y1 - 2001

N2 - We present an extension of the noncrossing approximation (NCA), which is widely used to calculate properties of Anderson impurity models in the limit of infinite Coulomb repulsion (formula presented) to the case of finite U. A self-consistent conserving pseudoparticle representation is derived by symmetrizing the usual NCA diagrams with respect to empty and doubly occupied local states. This requires an infinite summation of skeleton diagrams in the generating functional thus defining the “symmetrized finite-(formula presented) NCA” (SUNCA). We show that within SUNCA the low-energy scale (formula presented) (Kondo temperature) is correctly obtained, in contrast to other simpler approximations discussed in the literature.

AB - We present an extension of the noncrossing approximation (NCA), which is widely used to calculate properties of Anderson impurity models in the limit of infinite Coulomb repulsion (formula presented) to the case of finite U. A self-consistent conserving pseudoparticle representation is derived by symmetrizing the usual NCA diagrams with respect to empty and doubly occupied local states. This requires an infinite summation of skeleton diagrams in the generating functional thus defining the “symmetrized finite-(formula presented) NCA” (SUNCA). We show that within SUNCA the low-energy scale (formula presented) (Kondo temperature) is correctly obtained, in contrast to other simpler approximations discussed in the literature.

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U2 - 10.1103/PhysRevB.64.155111

DO - 10.1103/PhysRevB.64.155111

M3 - Article

AN - SCOPUS:85038907604

SN - 1098-0121

VL - 64

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 15

ER -