title: Nonlinear coupling of nanomechanical resonators to josephson quantum circuits.
abstract: We propose a technique to couple the position operator of a nanomechanical resonator to a SQUID device by modulating its magnetic flux bias. By tuning the magnetic field properly, either linear or quadratic couplings can be realized, with a discretely adjustable coupling strength. This provides a way to realize coherent nonlinear effects in a nanomechanical resonator by coupling it to a Josephson quantum circuit. As an example, we show how squeezing of the nanomechanical resonator state can be realized with this technique. We also propose a simple method to measure the uncertainty in the position of the nanomechanical resonator without quantum state tomography.
authors.affiliation: Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Xingxiang
authors.initials: X
authors.lastname: Zhou
authors.forename: Ari
authors.initials: A
authors.lastname: Mizel