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 have projected micron-scale light potentials onto quasi-2D degenerate Fermi gases of lithium-6. A single atomic layer is created by vertically compressing a 3D atomic cloud into a highly anisotropic blue-detuned TEM01-mode optical trap, with very weak in-layer confinement. A digital micromirror device (DMD) is then used here to mold the skyline of Florence in a unitary Fermi gas. The sample is imaged with micron resolution by the same high-resolution objective used for focusing the sculpted light potential. These new capabilities enable exciting investigations of fermionic quantum transport and out-of-equilibrium dynamics in a large variety of paradigmatic scenarios.

We theoretically investigate the onset of dissipation in the Josephson dynamics between two atomic Fermi superfluids. We demonstrate that resistive currents are directly connected with nucleations of vortex rings and their propagation into the superfluid bulk. We compare the simulations with our recent experimental results, finding excellent agreement. This work has been carried out in collaboration with the theory group of the University of Newcastle, led by Prof. Proukakis and it will be valuable for advancing our comprehension of the complex superfluid transport in emerging atomtronic devices.

K. Xhani et al.
Critical Transport and Vortex Dynamics in a Thin Atomic Josephson Junction
Phys. Rev. Lett. 124, 045301 (2020)

Despite its seeming simplicity, a Fermi gas of ultracold atoms with strong repulsive interactions exhibits a complex behavior, resulting from the competing action of two distinct instabilities — ferromagnetism and pairing. The breakdown of the repulsive Fermi liquid state, arising from such concurrent mechanisms, has been recently observed in real time through pump-probe spectroscopic techniques [A. Amico et al., Phys. Rev. Lett. 121, 253602 (2018)], leading also to the discovery of an emergent metastable microemulsion state of anticorrelated fermions and pairs. Here, we investigate the properties of such correlated many-body regime by preparing a strongly repulsive Fermi gas, and studying the evolution of kinetic and release energies, of the spectral response and coherence of the unpaired fermionic population, and of its spin-density noise correlations. All our observations consistently point to a low-temperature heterogeneous phase, where paired and unpaired fermions macroscopically coexist while exhibiting microscale inhomogeneity. Our findings open the exploration of quantum emulsions and possibly of inhomogeneous superfluid regimes.

F. Scazza et al.
Exploring emergent heterogeneous phases in strongly repulsive Fermi gases
Phys. Rev. A 101, 013603 (2020)

We show that the Lee-Huang-Yang (LHY) energy functional for a heteronuclear Bose mixture can be accurately approximated by an expression that has the same functional form as in the homonuclear case. It is characterized by two exponents, which can be treated as fitting parameters. We demonstrate that the values of these parameters which preserve the invariance under permutation of the two atomic species are exactly those of the homonuclear case. Deviations from the actual expression of LHY energy functional are discussed quantitatively.

F. Minardi et al.
Effective expression of the Lee-Huang-Yang energy functional for heteronuclear mixtures
Phys. Rev. A 100 063636 (2019)

Last Tweets

Seminars & Events

18.02.2020
Seminar by Prof. Carlos Sa de Melo:
Ultra-cold Fermi Gases with Three and Four Internal States: The Evolution from BCS to BEC Superfluidity in Multiband Systems ,
h. 12.00 Querzoli room, LENS.
13.02.2020
Seminar by Dr. Dimitrios Trypogeorgos:
Unconventional topology with a Rashba spin-orbit coupled quantum gas,
h. 14.30 Querzoli room, LENS.
09-10.05.2019
Firenze-Trieste workshop:
Two days of talks and scientific discussions with the theory groups of ICTP and SISSA,
ICTP, Trieste.
17-18.01.2019
Firenze-Trieste workshop:
Two days of talks and scientific discussions with the theory groups of ICTP and SISSA,
Aula Querzoli, LENS.
13.12.2018
Quantumgases retreat:
A full-day group meeting to discuss the activity of the different labs,
h. 9.00 Villa il Gioiello, Arcetri.
24.11.2017
Fermi Colloqium by Prof. Wolfgang Ketterle:
New forms of matter with ultracold atoms: superfluids, supersolids and more,
h. 11.30 Querzoli room, LENS.
27.09.2017
Seminar by Prof. Arno Rauschenbeutel:
Chiral Quantum Optics,
h. 11.00 Querzoli room, LENS.
13.06.2017
The LENS QuantumGases group is glad to welcome in Florence Prof. Randall Hulet from Rice University. Prof. Hulet will be our guest for one month until mid July.