Time-dependent quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator

TL;DR

This paper theoretically investigates the time-dependent quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator, revealing quantum-specific behaviors and energy transfer dynamics using non-equilibrium Green's function techniques.

Contribution

It introduces a non-perturbative approach to analyze the quantum dynamics of a nanomechanical oscillator coupled to electronic transport, highlighting differences from classical oscillators.

Findings

Quantum oscillator remains excited while classical dissipates energy.

Significant difference between quantum and classical oscillator behavior.

Insights into quantum state dynamics of nanomechanical systems.

Abstract

We present a theoretical study of time-dependent quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator within the non-equilibrium Green's function technique. An arbitrary voltage is applied to the tunnel junction and electrons in the leads are considered to be at zero temperature. The transient and the steady state behavior of the system is considered here in order to explore the quantum dynamics of the oscillator as a function of time. The properties of the phonon distribution of the nanomechnical oscillator strongly coupled to the electrons on the dot are investigated using a non-perturbative approach. We consider both the energy transferred from the electrons to the oscillator and the Fano factor as a function of time. We discuss the quantum dynamics of the nanomechanical oscillator in terms of pure and mixed states. We have found a significant difference between a quantum and a classical oscillator. In particular, the energy of a classical oscillator will always be dissipated by the electrons whereas the quantum oscillator remains in an excited state. This will provide useful insight for the design of experiments aimed at studying the quantum behavior of an oscillator.