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!

LAST NEWS

Quantum phase slips are the primary excitations in one-dimensional superfluids and superconductors at low temperature, but haven’t been so far detected in ultracold quantum gases. We have now studied experimentally the nucleation rate of phase slips in one-dimensional superfluids realized with ultracold quantum gases, owing along a periodic potential. We have observed a crossover between a regime of temperature-dependent dissipation at small velocity and interaction and a second regime of velocity-dependent dissipation at larger velocity and interaction. This behavior is consistent with the predicted crossover from thermally-assisted quantum phase slips to purely quantum phase slips.

L. Tanzi et al.
Velocity-dependent quantum phase slips in 1D atomic superfluids
arXiv:1603.05048 (2016), accepted by Scientific Report

We report the experimental observation of the full phase diagram across a transition where the spatial parity symmetry is broken. Our system consists of an ultra-cold gas of 39K with tunable interactions trapped in a double-well potential. At a critical value of the interaction strength, we observe a continuous quantum phase transition where the gas localizes in one well or the other, thus breaking the underlying symmetry of the system. Furthermore, we show the robustness of the asymmetric state against controlled energy mismatch between the two wells. This is the result of hysteresis associated with an additional discontinuous quantum phase transition that we fully characterize. Our results pave the way to the production of a broad class of quantum entangled states including Schroedinger cat states with macroscopic atom number.

A. Trenkwalder et al.,
Quantum phase transition with parity-symmetry breaking and hysteresis
Nature Phys. 12, 826 (2016)

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Seminars & Events

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.
20 & 21.04.2017
QUIC Project Meeting
See detailed program
Querzoli room, LENS.
10.04.2017
Seminar by Prof. Nick Proukakis:
Non-Equilibrium Dynamics in Quantum Gases,
h. 11.00 Querzoli room, LENS.
23.02.2017
Seminar by Prof. David Clément:
Momentum-resolved investigation of the condensate depletion in interacting Bose gases,
h. 15.00 Querzoli room, LENS.
22.02.2017
Seminar by Dr. Carmine Ortix:
Symmetry-protected topological insulators in one-dimension,
h. 12.00 Querzoli room, LENS.
08.02.2017
Trento-Florence Joint Meeting on Cold Matter
Polo Scientifico di Povo, Trento.
24.01.2017
Seminar by Dr. Franck Pereira Dos Santos:
Cold Atom Interferometry Gravity Sensors,
h.15.15 Querzoli room, LENS.
20.01.2017
Seminar by Andrea Morales:
Supersolid formation in a quantum gas breaking a continuous translational symmetry,
h.15.15 Querzoli room, LENS.
20.01.2017
Seminar by Prof. Jean-Philippe Brantut:
Mesoscopic transport experiments with cold atoms,
h. 11.00 Querzoli room, LENS.
19.12.2016
Seminar by Dr. Guido Pagano:
Observation of a Discrete Time Crystal in a Trapped-Ion Quantum Simulator,
h. 16.30 Querzoli room, LENS.
10.10.2016
Seminar by Dr. Francesco Piazza:
Spontaneous Crystallisation of Light and Ultracold Atoms,
h. 15.00 Querzoli room, LENS.
16.09.2016
Fermi Colloquim by Prof. Jun Ye:
Optical atomic clock and many-body quantum physics,
h. 11.30 Querzoli room, LENS.