Shot Noise of a Quantum Shuttle

TL;DR

This paper develops a theoretical framework for shot noise in quantum nanoelectromechanical systems and applies it to a quantum shuttle, revealing low noise levels in shuttling regimes and noise enhancement at the threshold.

Contribution

It introduces a new theory for shot noise in quantum nanoelectromechanical systems and demonstrates its application to quantum shuttles, highlighting noise behavior across regimes.

Findings

Fano factor reaches ~0.01 in quantum shuttling regime

Fano factor shows giant enhancement (~100) at shuttling threshold

Shuttling remains a low noise phenomenon in the quantum limit

Abstract

We formulate a theory for shot noise in quantum nanoelectromechanical systems. As a specific example, the theory is applied to a quantum shuttle, and the zero-frequency noise, measured by the Fano factor F, is computed. F reaches very low values (F~0.01) in the shuttling regime even in the quantum limit, confirming that shuttling is universally a low noise phenomenon. In approaching the semiclassical limit, the Fano factor shows a giant enhancement (F~100) at the shuttling threshold, consistent with predictions based on phase-space representations of the density matrix.