Unitary unraveling for the dissipative continuous spontaneous localization model: Application to optomechanical experiments

The continuous spontaneous localization (CSL) model strives to describe the quantum-to-classical transition from the viewpoint of collapse models. However, its original formulation suffers from a fundamental inconsistency in that it is explicitly energy nonconserving. Fortunately, a dissipative extension to CSL has been recently formulated that solves such an energy-divergence problem. We compare the predictions of the dissipative and nondissipative CSL models when various optomechanical settings are used and contrast such predictions with available experimental data, thus building the corresponding exclusion plots.

Figure 1

Experimental bounds on the dCSL parameters $\lambda$ and $r_{\text{C}}$ for two values of $T_{\text{CSL}}$. Left panel $T_{\text{CSL}}=1\mathrm{K}$ and right panel $T_{\text{CSL}}={10}^{-7}\mathrm{K}$. Purple (top-center) line and shadowed area: upper bound from the cantilever experiment [14]. Green, blue, and red (top-right, from left to right) lines and corresponding shadowed areas: upper bounds from gravitational wave detectors, respectively LISA Pathfinder [40], LIGO [41], and AURIGA [42]. Orange (top-left) and gray (bottom) regions: upper bound from cold atom experiment [16, 43] and lower bound from theoretical arguments [10]. The GRW [1] and the Adler [6, 7] values are reported in black.

Figure 2

Regime of validity of the conditions in [Eq. (12)] for the cantilever considered in Sec. 5a. The blue area denotes the values of $T_{\text{CSL}}$ and $r_{\text{C}}$ for which these conditions are fulfilled.