QUANTUM MONTE-CARLO STUDY OF THE TRANSPORT THROUGH A SMALL INTERACTING-SYSTEM

A numerical analysis for evaluating the transport coefficient through a small interacting system is examined using the quantum Monte Carlo ( QMC) method. To formulate the analysis, we consider a finite interacti ng system on a one-dimensional lattice that is connected to noninterac ting leads, and investigate the expression of the de conductance makin g use of the Kubo formula with the perturbation theory in the Coulomb interaction. At T=0 the de conductance is written in terms of the tran smission coefficient, which can be obtained numerically by extrapolati ng the QMC data for the Matsubara Green's function as is i epsilon(n)- ->i0(+). We apply the analysis to the de conductance through a region with a few resonance states.