Quantum Noise Interference and Backaction Cooling in Cavity Nanomechanics

We present a theoretical analysis of a novel cavity electromechanical system where a mechanical resonator directly modulates the damping rate kappa of a driven electromagnetic cavity. We show that via a destructive interference of quantum noise, the driven cavity can effectively act like a zero-temperature bath irrespective of the ratio kappa/omega(M), where omega(M) is the mechanical frequency. This scheme thus allows one to cool the mechanical resonator to its ground state without requiring the cavity to be in the so-called good cavity limit kappa <omega(M). The system described here could be implemented directly using setups similar to those used in recent experiments in cavity electromechanics.