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 reached simultaneous quantum degeneracy for fermionic Li and Cr atoms for the first time. In this work, we explain our all-optical strategy to realize large samples of more than 2x105 6Li and 105 53Cr atoms with T/TF as low as 0.25 in less than 13 s. Moreover, by use of a crossed bichromatic optical dipole trap, we are able to control the relative density and degree of degeneracy of the mixture components. This novel mass-imbalanced Fermi mixture, which we already proved to possess suitable Feshbach resonances in a previous work [Phys. Rev. Lett. 129, 093402 (2022)], opens the way to the observation of novel exotic few- and many-body phenomena, as well as the creation of ultracold polar paramagnetic LiCr molecules. Finally, our experimental methods can be exploited to realize large Fermi gases or homonuclear spin-mixtures of 53Cr, which will enable us to investigate the effects of weak dipolar interactions on BEC-BCS crossover physics.

Our results have been recently published in Physical Review A:

A. Ciamei et al.
Double-degenerate Fermi mixtures of 6Li and 53Cr atoms
Phys. Rev. A 106, 053318 (2022)

We studied the coupled dipole dynamics of a 41K-87Rb bosonic mixture as a function of the interspecies interaction. We measured both the frequency and the composition of the two dipole eigenmodes, from the weakly to the strongly attractive regime. For sufficiently strong interactions, even beyond the mean-field collapse, we found that the two condensates oscillate with the same frequency that depends only on the bare trap frequencies and the total mass of each species. This feature has been tested for a broad range of species population imbalance and has been demonstrated to agree with theoretical predictions.

L. Cavicchioli et al.
Dipole dynamics of an interacting bosonic mixture
Phys. Rev. Research 4, 043068 (2022)

In this work we experimentally demonstrate that the undo of an operation is possible also in quantum regimes. The last performed operation can be time-reversed via the undo command so as to perfectly restore a condition in which any new operation can be applied by an external user. We exploit the optimal control algorithm based on the dressed chopped random basis method, to perform several time-reversal transformations. We implement this algorithm by applying different levels of complexity, in terms of control, in order to manipulate the forward and backward internal state dynamics of a 87Rb Bose–Einstein condensate within an atom chip. As well as providing a thermodynamic interpretation of our results, in this paper we demonstrate that the quantum undo command can be performed also by time-reversing an operation in a generic instant of the past. The concept of quantum undo can be thus generalized. An external user, indeed, will be able to restore not only the last but also any past step of his complex computational routine. We are confident that our successful results could be applied in the next future on a real gate-based quantum computer.

I. Mastroserio, et al.,
Experimental Realization of Optimal Time-Reversal on an Atom Chip for Quantum Undo Operations
Adv. Quantum Technol. 2022, 2200057 (2022)

Paper appeared as back cover on Advanced Quantum Technologies 12/2022.

A large repulsion between particles in a quantum system can lead to their localization, an effect responsible for the Mott insulator phases in strongly correlated materials. In a system with multiple orbitals, an orbital-selective Mott insulator can form, where electrons in some orbitals are predicted to localize while others remain itinerant. Here we demonstrate a more general version of this phenomenon by observing flavour-selective localization in an atom-based quantum simulator. Our experiment realizes Fermi–Hubbard models with an SU(3) symmetry that can be broken using a tunable coupling between flavours. We observe an enhancement of the localization associated with a selective Mott transition and the emergence of flavour-dependent correlations. Our realization of flavour-selective Mott physics demonstrates the potential of cold atoms to simulate interacting multicomponent materials such as superconductors and topological insulators.

D. Tusi, et al.
Flavour-selective localization in interacting lattice fermions
Nat. Phys. 18, 1201 (2022)

Last Tweets

Seminars & Events

19-21.04.2022
Palaiseau-Florence Workshop on Ultracold Atoms:
Experimental and theoretical groups from Palaiseau (France) and Florence (Italy) research areas will present their activities and discuss collaborations. More info at quantumgases.lens.unifi.it/paf
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.