Theoretical study on quantum transport through strongly correlated electrons in quantum dots and nano materials

点击翻译按钮获取中文摘要

We have studied effects of inter-electron interaction on transport through quantum dots and nanoscale materials. We have proposed a novel large N expansion, where N is an orbital degeneracy. This method is different from the conventional ones and enables us a systematic calculation beyond the RPA. We have also obtained exact interacting Green's function for the Anderson impurity out of equilibrium at high bias voltages. Furthermore, we have provided an exact expression for nonequilibrium current fluctuations through a quantum dot, which includes a ferromagnetic Hund's rule coupling, in the low-energy Fermi liquid regime. Our result shows that the shot noise can be expressed in terms of renormalized parameters of quasiparticles defined with respect to equilibrium ground state in the particle-hole symmetric case. We have also studied interplay between Kondo and Andreev-Josephson effects of a quantum dot coupled to three terminals, consisting of normal and superconducting leads.