Full Counting Statistics of Electrons through Interaction of the Single Quantum Dot System with the Optical Field.

Weici Liu,Ruisheng Liang,Faqiang Wang,Zhilie Tang

doi:10.3390/nano9030394

Abstract

In this paper, using the particle-number-resolved master equation, the properties of full counting statistics (FCS) are investigated for a single quantum dot (QD) system interacting with optical fields in the thermal state, Fock state, coherent state, and coherent state with random phase. In these diverse quantum states of optical fields, average tunneling currents have different step shoulder heights at a lower bias voltage with the same light intensity, and a staircase-shaped current can be induced unexpectedly in vacuum state optical field. The characteristics of the Fano factor and skewness in the coherent state differ from those in all of the other cases. For avalanche-like transport at a lower bias voltage, the mechanism is a dynamical channel blockade in a moderate electron–photon interaction regime. There is a pronounced negative differential conductance that results from tuning the phase of the coherent state optical field in a symmetric QD system.

Highlights

The full counting statistics (FCS) of charge transfer in quantum dots (QDs), molecules, and nanostructures are an important component in the characterization of microscopic transport processes because the FCS contains complete information about low-frequency current fluctuations [1]
We apply a Hamiltonian with the quantum treatment of an optical field to study the influences of different quantum states of optical fields on the FCS properties of a QD in which the photon distribution is in equilibrium
The Fano factor-voltage characteristics for the thermal state, Fock state, and coherent state optical field, which is similar to that of the QD system interacting with a phonon [42]

Summary

Introduction

The full counting statistics (FCS) of charge transfer in quantum dots (QDs), molecules, and nanostructures are an important component in the characterization of microscopic transport processes because the FCS contains complete information about low-frequency current fluctuations [1]. The classical treatment for photons is valid at high field intensity and for the case of weak coupling in an equilibrium system, but it does not work in the vacuum state or other quantum states of light [22]. We apply a Hamiltonian with the quantum treatment of an optical field to study the influences of different quantum states of optical fields (thermal state, Fock state, coherent state, and coherent state with random phase) on the FCS properties of a QD in which the photon distribution is in equilibrium.

Physical Model and Formalism

Discussion

Conclusi1o0-1n2

Conclusion