Eur. Phys. J. B (2015) 88: 210
https://doi.org/10.1140/epjb/e2015-60102-x

Regular Article

Photon and phonon-assisted shot noise in a molecular quantum-dot-ferromagnetic system in the Coulomb blockade regime

School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China

^a e-mail: zhaohonk@bit.edu.cn

Received: 9 February 2015
Received in final form: 5 June 2015
Published online: 12 August 2015

Abstract

The dynamic shot noise in a molecular quantum dot connected to two non-collinear ferromagnetic terminals under the perturbation of ac fields has been investigated by the nonequilibrium Green’s function approach. The formulas of current, current correlation, and shot noise have been presented in the weak electron-phonon (el-ph) interaction regime to address the cooperated behaviors generated by the photon and phonon perturbation. The photon and phonon perturbations induce quite different current correlations, and the noise suppression occurs unambiguously by increasing the phonon energy in the valley regime. The suppression of shot noise comes from drawing the unbalanced current correlation towards the balanced one, where coherent current correlation takes major role. The suppression of photon-assisted shot noise can be completed mainly by rotating polarization angle of the terminals, and increasing the phonon energy ħω₀. The Fano factor is enhanced considerably by the el-ph interaction, and it is also enhanced by increasing the polarization angle from θ = 0 to θ = π.