A picture taken from a recent work of Luigi Seveso et al. is on the cover of Journal of Physics A. The paper is about the estimation of the mass of a quantum particle in a gravitational field and the seek of the ultimate bounds to precision for quantum-limited detection schemes.
Luigi and his coauthors have studied the effect of the field on the achievable sensitivity and addressed the question of whether quantumness of the probe state may provide a precision enhancement. They have shown that states with no classical limit perform better than semiclassical ones and that a non-trivial interplay exists between the external field and the statistical model. More intense fields generally lead to a better precision, with the exception of position measurements in the case of freely-falling systems (in agreement with the weak equivalence principle).
For more details, here is the link to the article on J. Phys. A.