Testing spontaneous localization theories with matter-wave interferometry

We propose to test the theory of continuous spontaneous localization (CSL) in an all-optical time-domain Talbot-Lau interferometer for clusters with masses exceeding ${10}^6\hspace{0.5em}$ amu. By assessing the relevant environmental decoherence mechanisms, as well as the growing size of the particles relative to the grating fringes, we argue that it will be feasible to test the quantum superposition principle in a mass range excluded by recent estimates of the CSL effect.

Figure 1

Critical mass $m_{\mathrm{c}}$ for testing continuous spontaneous localization (CSL) as a function of the localization rate ${\lambda }_0$, assuming the geometry of the proposed experiment with $N=2$. The shaded area indicates the parameter region where interference should be unobservable according to the CSL model. The dashed arrows mark the critical masses associated with reasonable estimates for the lower bound of ${\lambda }_0$ [6, 7].

Figure 2

Transmissivity [Eq. (7)] of the OTIMA interferometer vs the gold cluster mass. The dashed line (right scale) gives the laser flux, required to fix the visibility at $V=85\%$.

Figure 3

The contour lines give the critical residual gas pressures and the critical ambient temperatures for observing interference of gold clusters with masses of ${10}^6$, ${10}^7$, and ${10}^8$ amu.