Quasiparticle description for transport through a small interacting system
Abstract
We study the effects of electron correlation on transport through a small interacting system connected to reservoirs using an effective Hamiltonian which describes the free quasiparticles of a Fermi liquid. The effective Hamiltonian is defined microscopically with the value of the selfenergy at ω=0. Specifically, we apply the method to a Hubbard chain of finite size N (=1,2,3,...), and calculate the selfenergy within the second order in U in the electronholesymmetric case. When couplings between the chain and the reservoirs on the left and right are small, the conductance for even N decreases with increasing N, showing a tendency toward a MottHubbard insulator. This is caused by the offdiagonal element of the selfenergy, and this behavior is qualitatively different from that in the special case examined in previous work. We also study the effects of the asymmetry in the two couplings. While a perfect transmission due to the Kondo resonance occurs for any odd N in the symmetric coupling, the conductance for odd N decreases with increasing N in the case of asymmetric coupling.
 Publication:

Physical Review B
 Pub Date:
 March 2001
 DOI:
 10.1103/PhysRevB.63.115305
 arXiv:
 arXiv:condmat/0101002
 Bibcode:
 2001PhRvB..63k5305O
 Keywords:

 72.10.Bg;
 73.40.c;
 General formulation of transport theory;
 Electronic transport in interface structures;
 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 27 pages, RevTeX, 14 figures, to be published in Phys. Rev. B