A Simple Scheme for Quantum Non Demolition of Phonons Number of the   Nanoelectromechanics Systems
  In this work we describe a scheme to perform a continuous over time quantum non demolition (QND) mea- surement of the number of phonons of a nanoelectromechanical system (NEMS). Our scheme also allows us to describe the statistics of the number of phonons. 
F. R. de S. Nunes, J. J. I. de Souza, D. A. Souza, R. C. Viana and O.   P. de S\'a Neto
quant-ph