Laser-like Instabilities in Quantum Nano-electromechanical Systems

TL;DR

This paper explores negative damping phenomena in quantum nano-electromechanical systems, revealing laser-like instabilities, their scaling behavior, and the quantum fluctuations affecting oscillator coherence.

Contribution

It introduces a laser analogy to analyze negative damping in coupled mechanical and electronic quantum systems, highlighting new insights into their fluctuation physics and coherence properties.

Findings

Negative damping regimes induce laser-like instabilities.

Scaling laws relate system parameters to instability behavior.

Quantum fluctuations influence oscillator coherence and stability.

Abstract

We discuss negative damping regimes in quantum nano-electromechanical systems formed by coupling a mechanical oscillator to a single-electron transistor (normal or superconducting). Using an analogy to a laser with a tunable atom-field coupling, we demonstrate how these effects scale with system parameters. We also discuss the fluctuation physics of both the oscillator and the single-electron transistor in this regime, and the degree to which the oscillator motion is coherent.