We are excited to announce that Joel George has joined our group to pursue his PhD on quantum dynamics control using an integrable CMOS-compatible atom chip testbed. Joel’s project will focus on developing a load-lock system for the rapid replacement of atom chips without breaking the vacuum in the science cell. This innovative testbed will advance applications in atom interferometry, magnetometry, and quantum interfaces. His PhD is fully supported by the Marie Skłodowska Curie Action Matter Wave Interferometer (MAWI). Welcome aboard, and best of luck, Joel!

On October 30th-31st, we held the second Florence-Innsbruck joint meeting at the INO-CNR headquarters in Arcetri with the research groups on Ultracold Atoms from IQOQI and the University of Innsbruck. It was a great opportunity for the young researchers to discuss recent scientific advancements in a friendly atmosphere, surrounded by the beautiful setting of Arcetri. Many thanks to Giulia, Francesca, and Giacomo for the organization! See you in Innsbruck next year!

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)

Quantum gases of paramagnetic polar molecules, namely compounds that combine a large electric dipole moment with a magnetic one, associated with a nonzero electronic spin, are regarded as pristine platforms for a wealth of quantum-technological applications and fundamental studies ranging from quantum simulation and computation to controlled quantum chemistry and precision measurements. Yet realization of quantum gases of doubly polar molecules, based on biatomic systems considered so far, remains an unsurpassed task. In our joint experimental and theoretical work, we solve this two-decade-old challenge by exploring a new class of paramagnetic polar molecules, obtained by binding lithium alkali and transition-metal chromium elements. Starting from an ultracold mixture of 6⁢Li and 53⁢Cr fermionic atoms, we efficiently produce a high phase-space-density, long-lived gas of bosonic 6⁢Li53⁢Cr dimers, prepared within a single, weakly bound vibrational level. Through state-of-the-art techniques and novel probing methods, we reveal the paramagnetic nature of this diatomic species, gain experimental control over its internal quantum state, and identify the main inelastic mechanisms that may limit the system stability. In parallel, we develop quantum-chemical calculations to build a complete model for the LiCr molecule. We predict a large electric dipole moment together with high electronic spin in the absolute ground state, and we identify suitable transitions both for the coherent transfer of our weakly bound LiCr dimers to their lowest rovibrational level and for their subsequent optical manipulation. Our studies establish an unparalleled new pathway to realize quantum gases of doubly polar molecules, with countless future applications in quantum science and technology.

S. Finelli et al.
Ultracold Li⁢Cr: A New Pathway to Quantum Gases of Paramagnetic Polar Molecules
PRX Quantum (2024)