Interplay of Electron Phonon Coupling Dissipative Phonon Bath and Electron Electron Interaction in a Triangular Quantum-Dot Trimer

TL;DR

This paper investigates how electron-electron and electron-phonon interactions, along with phonon dissipation, influence charge transport in a triangular quantum-dot trimer molecular transistor using advanced theoretical models.

Contribution

It introduces a comprehensive theoretical framework combining Anderson Holstein Caldeira Leggett Hamiltonian with nonequilibrium Green's functions to analyze transport in quantum-dot systems.

Findings

Electron-phonon coupling significantly affects spectral functions.

Dissipation alters tunneling current and conductance.

Coulomb interactions modify transport characteristics.

Abstract

Nonequilibrium charge transport through a trimer molecular transistor composed of three quantum dots arranged in a triangular geometry, which is placed on a substrate, has been studied in the presence of electron electron and electron phonon interactions. The entire system is described by an extended Anderson Holstein Caldeira Leggett Hamiltonian, in which the Caldeira Leggett term accounts for phonon damping arising from the coupling between the molecular vibrations and the substrate phonon bath. The electron phonon interaction is treated nonperturbatively using the Lang Firsov canonical transformation, while the electron electron interaction is incorporated at the mean field level. Keldysh nonequilibrium Greens function framework is used to study the transport properties, allowing us to calculate the spectral function, tunneling current, ad differential conductance of the trimer molecular transistor. The formalism enables systematic evaluation of the effects of Coulomb interaction, electron phonon coupling, and dissipation on the devices electronic transport characteristics.