EPJ Quantum Technol. (2015) 2: 16
https://doi.org/10.1140/epjqt/s40507-015-0029-x

Research

Nonlinearity and nonclassicality in a nanomechanical resonator

¹ PHOTON-N2, Institut Pascal, Clermont Université, Blaise Pascal University, CNRS, Aubière Cedex, F-63177, France
² Dipartimento di Fisica, Università degli Studi di Milano, Milano, I-20133, Italia
³ Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen’s University, Belfast, BT7 1NN, UK

^* e-mail: matteo.paris@fisica.unimi.it

Received: 26 March 2015
Accepted: 16 June 2015
Published online: 3 July 2015

Abstract

We address quantitatively the relationship between the nonlinearity of a mechanical resonator and the nonclassicality of its ground state. In particular, we analyze the nonclassical properties of the nonlinear Duffing oscillator (being driven or not) as a paradigmatic example of a nonlinear nanomechanical resonator. We first discuss how to quantify the nonlinearity of this system and then show that the nonclassicality of the ground state, as measured by the volume occupied by the negative part of the Wigner function, monotonically increases with the nonlinearity in all the working regimes addressed in our study. Our results show quantitatively that nonlinearity is a resource to create nonclassical states in mechanical systems.