Using the inverse Abel transform, the in-situ 3D density profile of a cloud of two-state ⁶Li atoms trapped in a potential with cylindrical symmetry can be derived. Following [M. Ku et al., Science 335, 563 (2012)] we reconstruct the equation of state of the system. In particular, local pressure and compressibility have been obtained for the unitary Fermi gas, revealing the superfluid transition.

The quest to develop new and efficient experimental schemes to produce large and highly degenerate fermionic samples is fundamental in the way of using them to study fermionic superfluidity with a high degree of control on properties as interaction strength and dimensionality. ⁶Li samples of two spin components offers a broad Feshbach resonance allowing a good tenability of the interactions and the ability to investigate superfluidity across the BEC-BCS crossover. On the other way, standard laser cooling configurations are not efficient due to the lack of sub-Doppler cooling mechanism on the D2 line. We use a gray molasses operating on the D1 atomic transition to produce degenerate quantum gases of ⁶Li with a large number of atoms. This sub-Doppler cooling phase allows us to lower the initial temperature of 10⁹ atoms from 500 to 40 μK in 2 ms. We observe that D1 cooling remains effective into a high-intensity infrared dipole trap where two-state mixtures are evaporated to reach the degenerate regime. We produce molecular Bose-Einstein condensates of up to 5×10⁵ molecules and weakly interacting degenerate Fermi gases of 7×10⁵ atoms at T/T_F

A. Burchianti et al.
Efficient all-optical production of large ⁶Li quantum gases using D₁ gray-molasses cooling
Phys. Rev. A 90, 043408 (2014)

After testing the first cooling stages the experiment has been moved from LENS to the CNR research area in Pisa.

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.