Macroscopic tunneling of a membrane in an optomechanical double-well potential

The quantum tunneling of a macroscopic mechanical object is considered in a ``membrane-in-the-middle'' optomechanical resonator. We show theoretically that a cavity mode which couples quadratically to the membrane's position can create highly tunable adiabatic double-well potentials, which together with the high Q-factors demonstrated in such membranes render the observation of macroscopic quantum tunneling possible. We also show how a pulsed measurement scheme using a linearly coupled mode of the cavity can be used to monitor the tunneling.