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

We use a bichromatic optical lattice to experimentally realize a disordered system of ultracold strongly interacting 87Rb bosons. In the absence of disorder, the atoms are pinned by repulsive interactions in the sites of an ideal optical crystal, forming one-dimensional Mott-insulator states. We measure the excitation spectrum of the system as a function of disorder strength and characterize its phase-coherence properties with a time-of-flight technique. Increasing disorder, we observe a broadening of the Mott-insulator resonances and the transition to a state with vanishing long-range phase coherence and a flat density of excitations, which suggest the formation of a Bose-glass phase.

L. Fallani et al.
Ultracold Atoms in a Disordered Crystal of Light: Towards a Bose Glass
Phys. Rev. Lett. 98, 130404 (2007)

We have performed pioneering investigations of a Bose-Einstein condensate in a random potential, produced by shining an optical speckle pattern onto the atoms. We have investigated both static and dynamic properties of the BEC in the presence of disorder. With small levels of disorder, stripes are observed in the expanded density profile and strong damping of dipole and quadrupole oscillations is seen. By studying the propagation of the BEC in a disordered waveguide, we have evidenced a strong suppression of mass transport as the speckle potential is increased. The experimental results are in good agreement with numerical calculations based on the Gross-Pitaevskii equation.

J. E. Lye et al.
Bose-Einstein Condensate in a Random Potential
Phys. Rev. Lett. 95, 070401 (2005)

C. Fort et al.
Effect of Optical Disorder and Single Defects on the Expansion of a Bose-Einstein Condensate in a One-Dimensional Waveguide
Phys. Rev. Lett. 95, 170410 (2005)

We have experimentally studied the unstable dynamics of a harmonically trapped Bose-Einstein condensate loaded into a 1D moving optical lattice. The lifetime of the condensate in such a potential exhibits a dramatic dependence on the quasimomentum state. This is unambiguously attributed to the onset of dynamical instability, after a comparison with the predictions of the Gross-Pitaevskii theory. Deeply in the unstable region we observe the rapid appearance of complex structures in the atomic density profile, as a consequence of the condensate phase uniformity breakdown.

L. Fallani et al.
Observation of Dynamical Instability for a Bose-Einstein Condensate in a Moving 1D Optical Lattice
Phys. Rev. Lett. 93, 140406 (2004)

We report the experimental observation of a lensing effect on a Bose-Einstein condensate expanding in a moving 1D optical lattice. The effect of the periodic potential can be described by an effective mass dependent on the condensate quasimomentum. By changing the velocity of the atoms in the frame of the optical lattice, we induce a focusing of the condensate along the lattice direction. The experimental results are compared with the numerical predictions of an effective 1D theoretical model. In addition, a precise band spectroscopy of the system is carried out by looking at the real-space propagation of the atomic wave packet in the optical lattice.

L. Fallani et al.
Optically Induced Lensing Effect on a Bose-Einstein Condensate Expanding in a Moving Lattice
Phys. Rev. Lett. 91, 240405 (2003)

Last Tweets

Seminars & Events

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.
23.11.2017
Prof. Wolfgang Ketterle will give a lecture for students and everyone else interested on the topic:
Superfluid Bose and Fermi gases,
h. 15.00 Room 25, Blocco Aule.
27.09.2017
Seminar by Prof. Arno Rauschenbeutel:
Chiral Quantum Optics,
h. 11.00 Querzoli room, LENS.
19.07.2017
Seminar by Prof. Maarten Hoogerland:
Atomtronics and cavity QED experiments in Auckland,
h. 11.30 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.
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.