Spin-dependent Andreev Conductance And Shot Noise In A Quantum Dot With Phonon Modes

In this paper, using nonequilibrium Green's function technique, we study the tansport properties of the ferromagnet/quantum dot/superconductor system. We calculate the effects on the Andreev reflection conductance and shot noise caused by electron-phonon interaction. The works of this paper includes:1. Building on the nonequilibrium Green's function and a canonical transformation of the electron-phonon interaction, we drive the formulation of the AR conductance and shot noise.2. We calculate the AR conductance and shot noise of our mode. The results show that, electron-phonon interaction leads to new statellite resonant peaks(phonon peaks) which are located exactly on the integer number of the phonon frequency. Moreover, the height of phonon peaks is sensitive to the electron-phonon coupling. The phonon peaks appear in the shot noise also. The phonon peaks looks more clearly in shot noise than that in AR conductance.3. We study the AR conductance on the conditions of different spin-flip scattering and differnt couplings between the qutaum dot and the leads. It's found that the compete between them dominion the AR conductance properties.