Negative Differential Conductance Assisted by Optical Fields in a Single Quantum Dot with Ferromagnetic Electrodes

Abstract

In a single quantum dot (QD) system connected with ferromagnetic electrodes, the electron transport properties, assisted by the thermal and Fock state optical fields, are theoretically studied by the Keldysh nonequilibrium Green’s function approach. The results show that the evolution properties of the density of state and tunneling current assisted by the Fock state optical field, are quite different from those of the thermal state. The photon sideband shift decreases monotonously with the increase in the electron–photon coupling strength for the case of the thermal state, while the shift is oscillatory for the case of the Fock state. Negative differential conductance (NDC) appears obviously in a QD system contacted with parallel (P) and antiparallel (AP) magnetization alignment of the ferromagnetic electrode leads, assisted by the Fock state optical field in a wide range of electron–photon interaction parameters. Evident NDC usually only arises in an AP configuration QD system assisted by the thermal state optical field. The results have the potential to introduce a new way to actively manipulate and control the single-electron tunneling transport on a QD system by the quantum states of the optical field.

Spatial spin-spin correlations of the single-impurity Anderson model with a ferromagnetic bath

“…These works mainly explored how the local properties are influenced by the spin polarized electrodes, studying quantities like the QD spectral function, conductance, differential conductance, or the occupation of the QD level [5][6][7][8][9][10][11][16][17][18] . Compared to the local properties, far less is known on how the non-local properties are influenced by the ferromagnetic electrodes.…”

Polaronic effects induced by non-equilibrium vibrons in a single-molecule transistor

“…8 ). There are only few papers [9][10][11] , where vibrons in electron transport in SET were considered as non-equilibrated. In Ref.…”