Energy pumping in a quantum nanoelectromechanical system

TL;DR

This paper investigates how a quantum dot coupled to electronic leads exhibits different mechanical excitation regimes depending on applied voltage, revealing a threshold-driven energy pumping effect.

Contribution

It introduces a detailed analysis of energy pumping in a fully quantized nanoelectromechanical system with voltage-dependent regimes.

Findings

Below threshold, mechanical excitation remains low.

Above threshold, mechanical energy increases dramatically.

Distribution functions and current are calculated in the high-energy regime.

Abstract

Fully quantized mechanical motion of a single-level quantum dot coupled to two voltage biased electronic leads is studied. It is found that there are two different regimes depending on the applied voltage. If the bias voltage is below a certain threshold (which depends on the energy of the vibrational quanta) the mechanical subsystem is characterized by a low level of excitation. Above a threshold the energy accumulated in the mechanical degree of freedom dramatically increases. The distribution function for the energy level population and the current through the system in this regime is calculated.