Nonequilibrium Fluctuations and Decoherence in Nanomechanical Devices Coupled to the Tunnel Junction

TL;DR

This paper investigates how nonequilibrium fluctuations influence decoherence and current behavior in nanomechanical oscillators coupled to tunnel junctions, revealing quantum heating effects and nonlinear current-voltage characteristics.

Contribution

It provides explicit formulas for oscillator fluctuations, damping, and current, considering arbitrary voltages and temperatures, highlighting quantum heating and vacuum fluctuation effects.

Findings

Quantum heating causes nonlinear I-V characteristics.

Fluctuations and decoherence rates are explicitly derived.

Mechanical vacuum fluctuations impact oscillator dynamics.

Abstract

We analyze the dynamics of a nanomechanical oscillator coupled to an electrical tunnel junction with an arbitrary voltage applied to the junction and arbitrary temperature of electrons in leads. We obtain the explicit expressions for the fluctuations of oscillator position, its damping/decoherence rate, and the current through the structure. It is shown that quantum heating of the oscillator results in nonlinearity of the current-voltage characteristics. The effects of mechanical vacuum fluctuations are also discussed.