Dephasing of electrons in the Aharonov-Bohm interferometer with a single-molecular vibrational junction

TL;DR

This paper investigates how electron phase coherence is affected by vibrational states in a molecular junction within an Aharonov-Bohm interferometer, revealing robustness of phase shifts against various parameters.

Contribution

It introduces a quantum master equation approach to analyze electron phase relaxation caused by vibrational excitations in a molecular junction.

Findings

Electron coherence is partially destroyed by scattering on vibrational levels.

Transmission phases differ by π between adjacent vibrational states.

The π phase shift depends only on the oscillator frequency and is robust across parameter variations.

Abstract

Phase relaxation of electrons transferring through an electromechanical transistor is studied using the Aharonov-Bohm interferometer. With the approach of quantum master equation, the phase properties of an electron are numerically analyzed based on the interference fringes. Coherence of electron is partially destroyed by its scattering on excited levels of the local nanomechanical oscillator. Transmission amplitudes with respect to two adjacent mechanical vibrational levels have a phase difference of $\pi$. The character of phase shift by $\pi$ depends on the oscillator frequency only and is robust for the wide range variance of the applied voltage, tunneling length and damping rate of the mechanical oscillator.