Taming, slowing and trapping atoms with light
Cold is quantum, Quantum is cool!
We shape quantum matter
Multicolored lasers for a variety of atoms
Keeping our eyes on the quantum world
Join our ultracool group!
High technology for great science

Welcome to the website of the Ultracold Quantum Gases group at the European Laboratory for Nonlinear Spectroscopy (LENS), the Department of Physics and Astronomy of the University of Florence (Italy) and the Institute of Optics of the Italian National Research Council (CNR - INO). In our labs we use lasers and magnetic fields to produce the lowest temperatures of the Universe, just a few billionths of a degree above absolute zero...

At these temperatures, atoms stop moving and we can control them for a variety of different fundamental studies and applications. We can force atoms to arrange according to a periodic structure and simulate the behavior of crystalline solids and new materials. We can use the atoms as ultra-high accurate sensors to probe forces with the power of quantum mechanics. We can study how quantum particles combine together under the action of strong interactions and how superfluidity develops. We can use these ultracold atoms to process information and develop new quantum technologies.

Dress warmly and... follow us for this ultracold journey!

LAST NEWS

We study the ultimate bounds on the sensitivity of a Bloch-oscillation atom interferometer where the external force is estimated from the measurement of the on-site atomic density. For external forces such that the energy difference between lattice sites is smaller than the tunneling energy, the atomic wave-function spreads over many lattice sites, increasing the separation between the occupied modes of the lattice and naturally enhancing the sensitivity of the interferometer. To investigate the applicability of this scheme we estimate the effect of uncontrolled fluctuations of the tunneling energy and the finite resolution of the atom detection. Our analysis shows that a horizontal lattice combined with a weak external force allow for high sensitivities. Therefore, this setup is a promising solution for compact devices or for measurements with high spatial resolution.

I. Nałȩcz, et al.,
Sensitivity bounds of a spatial Bloch-oscillation atom interferometer
Phys. Rev. A 102, 033318 (2020)

When two superconductors are coupled with one another through an insulating junction, a so-called Josephson supercurrent may flow without creating any potential difference, sustained merely by a phase difference between the superconducting wave functions. We have observed the charge-neutral analogue of this phenomenon using an ultracold gas of strongly interacting fermionic atoms, revealing the quintessential sinusoidal relationship between the supercurrent and the superfluid phase. Our experiments demonstrate the profound connection between the supercurrent magnitude and the nature of superfluid states, which has allowed us to quantify the condensate density across the BCS-BEC crossover of ultracold Fermi gases, playing the role of the superfluid order parameter.

W. J. Kwon et al.
Strongly correlated superfluid order parameters from dc Josephson supercurrents
Science 369, 84 (2020)

In the middle of the hot Tuscan summer, we could bring to quantum degeneracy large samples of 6Li atoms in our setup. With the same all-optical strategies already developed in the LiLab, we can achieve crossover superfluids, as well as highly degenerate Fermi gases, of up to 1 million atoms. (In the image, the hydrodynamic expansion of a crossover superfluid of about 700000 pairs).

Seminars & Events

17-19.04.2023
InnFi Joint Meeting on Ultracold Atoms:
Experimental and theoretical groups from Innsbruck (Austria) and Florence (Italy) research areas will present their activities and discuss collaborations. Click here for more info.