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Perturbation Study of the Conductance through an Interacting Region Connected to Multi-Mode Leads

Yoshihide Tanaka·Akira Oguri·Hiroumi Ishii
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Abstract

We study the effects of electron correlation on transport through an interacting region connected to multi-mode leads based on the perturbation expansion with respect to the inter-electron interaction. At zero temperature the conductance defined in the Kubo formalism can be written in terms of a single-particle Green's function at the Fermi energy, and it can be mapped onto a transmission coefficient of the free quasiparticles described by an effective Hamiltonian. We apply this formulation to a two-dimensional Hubbard model of finite size connected to two noninteracting leads. We calculate the conductance in the electron-hole symmetric case using the order $U^2$ self-energy. The conductance shows several maximums in the $U$ dependence in some parameter regions of $t_y/t_x$, where $t_x$ ($t_y$) is the hopping matrix element in the $x$- ($y$-) directions. This is caused by the resonance occurring in some of the subbands, and is related with the $U$ dependence of the eigenvalues of the effective Hamiltonian.

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Yoshihide Tanaka, Akira Oguri, Hiroumi Ishii. 2001-10-31. Perturbation Study of the Conductance through an Interacting Region Connected to Multi-Mode Leads. https://doi.org/10.1143/jpsj.71.211

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