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

Max Schemmer has joined the LiCr team as Senior researcher.
Max has previously worked on 1-D quantum gases during his PhD under supervision of Isabelle Bouchoule (Laboratoire Charles Fabry, Palaiseau, France), and has has later worked as Marie-Curie fellow on quantum optics with cold atom-optical nanofiber hybrid platforms in the group of Arno Rauschenbeutel (Humboldt Universität zu Berlin).

Viel Glück Max!

Alessio Ciamei and Max Schemmer have both won the "Young Researcher" grant funded by the Italian Ministry of University and Research (MUR) with 300k€, each for the next 3 years.
A. C. will realize an ultracold gas of Polar Paramagnetic Molecules (PoPaMol) of LiCr and exploit this new class of molecules to perform ultracold chemistry studies and high precision spectroscopy.
M. S. plans to reveal Majorana states in Li-Cr p-wave superfluids, paving the way for topological quantum computing (MajorSuperQ).

Buona fortuna a entrambi!

Persistent currents in a ring are one of the most striking manifestations of quantum system coherence. The periodic boundary constrains the wavefunction phase to wind in an integer number of complete loops, which gives rise to a current. This happens in materials with a macroscopic coherence, like superconductors or neutral superfluids, but also in mesoscopic metallic rings. Besides being a proxy of quantum phase coherence, persistent currents represent a cornerstone for many applications, from precision sensing to quantum computing, that require a fast and controlled current injection and a reliable readout of its magnitude. In our work, we realize a fast and on-demand generation of persistent currents in atomic Fermi superfluid rings and investigate their connection with vortex nucleation.
We excite persistent current states of on-demand winding number by dynamically imprinting the phase winding in the ring with a tailored laser beam. Using an interferometric probe, we directly accesses the ring phase profile and we consequently readout the current state. We apply our method to an atomic Fermi gas in different interaction regimes, ranging from a bosonic to a fermionic superfluid. Persistent currents in these rotating neutral superfluids are metastable states, interrupted only by a phase slippage that tears out the phase winding. We finally induce the current decay by inserting a small defect in the ring. For currents higher than a critical value, the obstacle triggers the emission of vortices, which reduce the phase winding.
Our work demonstrates fast and accurate control of persistent currents in strongly interacting fermionic superfluids, opening the route for their application in quantum technologies.

G. Del Pace et al.
Imprinting Persistent Currents in Tunable Fermionic Rings
Phys. Rev. X 12, 041037 (2022)

Vladislav Gavryusev has received a grant for his project MicroSpinEnergy funded by the Italian Ministry of University and Research (MUR) and has become a fixed-term researcher in Physics of Matter at the Department of Physics and Astronomy. In the next three years he will translate advanced microscopy methods to investigate quantum spin models and energy transport in finely engineered systems of Sr atoms in optical tweezers with single particle control.

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)

Seminars & Events

17-19.04.2023
InnFi Joint Meeting on Ultracold Atoms:
Experimental and theoretical groups from Innsbruck (Austria) and Florence (Italy) research areas will present their activities and discuss collaborations. Click here for more info.