Coherent transport through a resonant level coupled to random-matrix leads

Abstract

We study the transport through a resonant level coupled to two leads with the latter being described by Wigner's random matrices. By taking appropriate thermodynamic limit before taking the long time limit, we obtain the stationary current as a function of voltage bias. The I-V curve is similar to that of single impurity Anderson model. On the other hand, the current matrix and initial density matrix in our model look like random matrices in the eigenbasis of Hamiltonian. They satisfy the description of eigenstate thermalization hypothesis (ETH) and nonequilibrium steady state hypothesis (NESSH), respectively. A statistical formula of current has been derived based on ETH and NESSH (J. Stat. Mech.: Theo. Exp., 093105 (2017)). We check this formula in our model and find it to predict the stationary current to a high precision. The shape of I-V curve is explained by the peak structure in the characteristic function of NESSH, which is reminiscent of the transmission coefficient.