Magneto-transport properties of a single molecular transistor in the presence of electron-electron and electron-phonon interactions and quantum dissipation

Manasa Kalla,Ashok Chatterjee,Narasimha Raju Chebrolu

doi:10.1038/s41598-019-53008-5

Manasa Kalla, Ashok Chatterjee + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-53008-5

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Journal: Scientific Reports	Publication Date: Nov 11, 2019
Citations: 9	License type: open-access

Affiliation: University of Hyderabad, University of Seoul

Abstract

A single molecular transistor is considered in the presence of electron-electron interaction, electron-phonon interaction, an external magnetic field and dissipation. The quantum transport properties of the system are investigated using the Anderson-Holstein Hamiltonian together with the Caldeira-Leggett model that takes care of the damping effect. The phonons are first removed from the theory by averaging the Hamiltonian with respect to a coherent phonon state and the resultant electronic Hamiltonian is finally solved with the help of the Green function technique due to Keldysh. The spectral function, spin-polarized current densities, differential conductance and spin polarization current are determined.

Highlights

A single molecular transistor is considered in the presence of electron-electron interaction, electronphonon interaction, an external magnetic field and dissipation
We have studied the non-equilibrium transport properties of an single molecular transistor (SMT) device in the presence of el-el and el-ph interactions, external magnetic field and phononic dissipation
We have modeled the device by Anderson-Holstein-Caldeira-Leggett Hamiltonian and used Keldysh Green’s function method to calculate the spectral function A, current density J, differential conductance G and spin polarization parameter Pσ, −σ

Summary

Introduction

A single molecular transistor is considered in the presence of electron-electron interaction, electronphonon interaction, an external magnetic field and dissipation. Where ndσ(=cd†σcdσ) represents the number operator for the QD electrons with energy εd, cd†σ(cdσ) being the corresponding electron creation (annihilation) operator, Vg denotes the gate voltage, U gives the measure of the onsite e-e interaction, B (0, 0, B) refers to the magnetic field, Sdz stands for the total spin of the QD electrons along the z direction, b†(b) creates (destroys) a QD phonon with frequency ω0 which is considered dispersionless and λ denotes the e-p coupling constant.

Results

Conclusion