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

Welcome to the website of the Ultracold Quantum Gases group at the European Laboratory for Nonlinear Spectroscopy (LENS) and Department of Physics and Astronomy of the University of Florence (Italy). 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!


Anderson localization is a universal phenomenon affecting non-interacting quantum particles in a disordered environment. In three spatial dimensions, theory predicts a quantum phase transition from localization to diffusion at a critical energy, the mobility edge, which depends on the disorder strength. Although it has been recognized already long ago as a prominent feature of disordered systems, a complete experimental characterization of the mobility edge is still missing. Here we report the measurement of the mobility edge for ultracold atoms in a disordered potential created by laser speckles. We are able to control both the disorder strength and the energy of the system, so as to probe the position of the localization threshold in the disorder–energy plane. Our results might allow a direct experiment–theory comparison, which is a prerequisite to study the even more challenging problem of disorder and interactions.

G. Semeghini, et al.,
Measurement of the mobility edge for 3D Anderson localization
Nature Phys. 11, 554 (2015)

We aim at studying two-dimensional fermionic 6Li atoms across the BCS-BEC crossover. We plan to benefit of the recent advances in ultracold atomic systems, such as single-site addressability and the full control of the interparticle interactions. Tailoring arbitrary optical potentials will create the perfect environment for implementing quantum models. In particular, we want to characterize the superfluid phase by studying the interlayer tunneling, discriminating the coherent Josephson dynamics from the single-particle hopping. By adding disorder we will simulate the physics of granular superconductors, testing the robustness of the order parameter and the onset of metallic phases at higher temperatures.

Differential interferometry (DI) with two coupled sensors is a most powerful approach for precision measurements in the presence of strong phase noise. However, DI has been studied and implemented only with classical resources. Here we generalize the theory of differential interferometry to the case of entangled probe states. We demonstrate that, for perfectly correlated interferometers and in the presence of arbitrary large phase noise, sub-shot noise sensitivities — up to the Heisenberg limit — are still possible with a special class of entangled states in the ideal lossless scenario.

M. Landini et al.,
Phase-noise protection in quantum-enhanced differential interferometry
New J. Phys. 16, 113074 (2014)

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Seminars & Events

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.
20 & 21.04.2017
QUIC Project Meeting
See detailed program
Querzoli room, LENS.
Seminar by Prof. Nick Proukakis:
Non-Equilibrium Dynamics in Quantum Gases,
h. 11.00 Querzoli room, LENS.
Seminar by Prof. David Clément:
Momentum-resolved investigation of the condensate depletion in interacting Bose gases,
h. 15.00 Querzoli room, LENS.
Seminar by Dr. Carmine Ortix:
Symmetry-protected topological insulators in one-dimension,
h. 12.00 Querzoli room, LENS.
Trento-Florence Joint Meeting on Cold Matter
Polo Scientifico di Povo, Trento.
Seminar by Dr. Franck Pereira Dos Santos:
Cold Atom Interferometry Gravity Sensors,
h.15.15 Querzoli room, LENS.
Seminar by Andrea Morales:
Supersolid formation in a quantum gas breaking a continuous translational symmetry,
h.15.15 Querzoli room, LENS.
Seminar by Prof. Jean-Philippe Brantut:
Mesoscopic transport experiments with cold atoms,
h. 11.00 Querzoli room, LENS.
Seminar by Dr. Guido Pagano:
Observation of a Discrete Time Crystal in a Trapped-Ion Quantum Simulator,
h. 16.30 Querzoli room, LENS.
Seminar by Dr. Francesco Piazza:
Spontaneous Crystallisation of Light and Ultracold Atoms,
h. 15.00 Querzoli room, LENS.
Fermi Colloquim by Prof. Jun Ye:
Optical atomic clock and many-body quantum physics,
h. 11.30 Querzoli room, LENS.