Quest for Quantum Superpositions of a Mirror: High and Moderately Low Temperatures

The Born-Markov master equation analysis of the vibrating mirror and photon experiment proposed by Marshall, Simon, Penrose, and Bouwmeester is completed by including the important issues of temperature and friction. We find that at the level of cooling available to date, visibility revivals are purely classical, and no quantum effect can be detected by the setup, no matter how strong the photon-mirror coupling is. Checking proposals of universal nonenvironmental decoherence is ruled out by dominating thermal decoherence; a conjectured coordinate-diffusion contribution to decoherence may become observable on reaching moderately low temperatures.

Figure 1

Contours of equal visibility (white for good, black for poor), as a function of temperature $T$ and friction $\gamma$, based on Eqs. (11, 12, 14). Upper-right corner, present-state possibilities; dashed line, where CLS decoherence becomes observable. The turnback of the contours in the lower-right corner corresponds to the coordinate-diffusion contribution [8], with $\kappa =1$ and $\lambda =1$.