2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/23408We 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.4 pages, 2 figures; minor formal changes - updated figures and references; final version as published in Phys. Rev. LettMesoscale and Nanoscale Physicstext