Andreev reflection and shot noise in a quantum dot with phonon modes

J Phys Condens Matter. 2009 Mar 4;21(9):095602. doi: 10.1088/0953-8984/21/9/095602. Epub 2009 Feb 4.

Abstract

Building on the nonequilibrium Green's function technique and a canonical transformation of the electron-phonon interaction, this paper focuses on the study of the Andreev reflection conductance and the shot noise in a single quantum dot coupling with local phonon modes. The effect of the intradot spin-flip interaction on the transport properties is considered. We pay attention to the effects of the phonon on the Andreev reflection conductance and the shot noise. It is found that splits due to spin-flip scattering appear not only in the main Andreev reflection peaks but also in the new satellite peaks. The electron-phonon interaction leads to new satellite resonant peaks that are located exactly on the integer number of the phonon frequency. Moreover, the peak height is sensitive to the electron-phonon coupling. Even if the electron-phonon coupling is weak, the shot noise spectrum shows the phonon mode peaks rather clearly, but in the Andreev reflection conductance the phonon mode peaks weakly.