Just as a thin water jet emerging from a tap, a quantum atomic filament may break up into droplets: surprisingly, under some circumstances, quantum gases behave like liquids. In our lab, we prepare a quantum droplet of ⁴¹K and ⁸⁷Rb, and release it in an optical waveguide. The droplet expands along the waveguide up to a critical length, and then splits into two or more sub-droplets. Our results can be explained in terms of capillary instability, previously observed in a variety of physical systems, including ordinary liquids and superfluid helium, but not yet in the ultracold gas realm. Getting curious? Look it up on the arxiv!

L. Cavicchioli et al.
Dynamical formation of multiple quantum droplets in a Bose-Bose mixture
arXiv:2409.16017 (2024)

In a multi-level quantum system Fano coherences stand for the formation of quantum coherences due to the interaction with the continuum of modes characterizing an incoherent process. In this paper we propose a V-type three-level quantum system on which we certify the presence of genuinely quantum traits underlying the generation of Fano coherences. We do this by determining work conditions that allows for the loss of positivity of the Kirkwood-Dirac quasiprobability distribution of the stochastic energy changes within the discrete system. We also show the existence of nonequilibrium regimes where the generation of Fano coherences leads to a non-negligible excess energy given by the amount of energy that is left over with respect to the energy of the system at the beginning of the transformation. Excess energy is attained provided the initial state of the discrete system is in a superposition of the energy eigenbasis. We conclude the paper by studying the thermodynamic efficiency of the whole process.

L. Donati et al.
Energetics and quantumness of Fano coherence generatio
Scientific Report 14, 20145 (2024)

We have atoms trapped in optical tweezers! The journey has been long, and the excitement in the lab was palpable when we saw the first signatures in fluorescence imaging. The next important step will be to implement light-assisted collisions and in-trap cooling to reach single atom occupancy per tweezer!

Big news from the lab! After months of hard work, we’ve successfully developed both a broadband red MOT and a single-frequency red MOT. The atom density is up to two orders of magnitude larger than in the blue MOT, while the temperature is approximately 10 micro Kelvin. Now we’re excited to take the next step—time to trap some atoms in optical tweezers!

Yasir Mehmood has joined our group to pursue his PhD on atom-resonant entangled photon sources. Welcome and best of luck, Yasir!