We finished assembling the vacuum setup. In the final cell, we included a passive high finesse optical resonator to transfer a large volume of atoms from the MOT to an optical trap that requires low power.

Global Positioning System (GPS) dissemination of frequency standards is ubiquitous at present, providing the most widespread time and frequency reference for the majority of industrial and research applications worldwide. On the other hand, the ultimate limits of the GPS presently curb further advances in high-precision, scientific and industrial applications relying on this dissemination scheme. Here, we demonstrate that these limits can be reliably overcome even in laboratories without a local atomic clock by replacing the GPS with a 642-km-long optical fiber link to a remote primary caesium frequency standard. Through this configuration we stably address the ¹S₀ → ³P₀ clock transition in an ultracold gas of ¹⁷³Yb, with a precision that exceeds the possibilities of a GPS-based measurement, dismissing the need for a local clock infrastructure to perform beyond-GPS high-precision tasks. We also report an improvement of two orders of magnitude in the accuracy on the transition frequency reported in literature.

C. Clivati et al.,
Measuring absolute frequencies beyond the GPS limit via long-haul optical frequency dissemination
Opt. Express 24, 11865 (2016)

We have completed the design of the dual-species vacuum setup of the experiment and its construction will begin very soon. Stay tuned for updates!

We have recently developed a home-made and unexpensive high power laser source @425nm: up to 800mW of blue light for laser cooling of Chromium!

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
Scientific Reports 6, 25965 (2016)