Pushing the limits of atom interferometry...The system we want to realize is a Mach-Zender spatial interferometer operating with trapped Bose-Einstein condensates (BECs). Phase diffusion caused by interatomic collisions are suppressed implementing BECs with tunable interactions in ultra-stable optical potentials. Entangled states can be used to improve the sensitivity of the sensor beyond the standard quantum limit to ideally reach the ultimate, Heisenberg, limit set by quantum mechanics. Our project aims at developing a sensor with unprecedented spatial resolution able to compete with, and eventually overcome, state-of-the-art interferometers with cold (non condensed) atomic waves.

Close encounters between quantum droplets

We report on the study of binary collisions between quantum droplets formed by an attractive mixture of ultracold atoms. We distinguish two main outcomes of the collision, i.e., merging and separation, depending on the velocity of the colliding pair. The critical velocity vc that discriminates between the two cases displays a different dependence on the atom number N for small and large droplets. By comparing our experimental results with numerical simulations, we show that the nonmonotonic behavior of vc is due to the crossover from a compressible to an incompressible regime, where the collisional dynamics is governed by different energy scales, i.e., the droplet binding energy and the surface tension. These results also provide the first evidence of the liquidlike nature of quantum droplets in the large N limit, where their behavior closely resembles that of classical liquid droplets.

G. Ferioli et al.,
Collisions of Self-Bound Quantum Droplets
Phys. Rev. Lett. 122, 090401 (2019)

K2 people

Tommaso Petrucciani
PhD student
Leonardo Masi
PhD student
Giovanni Ferioli
Postdoctoral fellow
Giovanni Modugno
Scientific staff
Massimo Inguscio
Scientific staff
Marco Fattori
Scientific staff
Former members:
Simon Coop
Manuele Landini
Sanjukta Roy
Giulia Semeghini
Giacomo Spagnolli
Andreas Trenkwalder

K2 contacts

For further information, request of material, job opportunities, please contact:

Marco Fattori
(fattori@lens.unifi.it)

K2 funding

ERC StG AISENS
EU FP7 QIBEC
QuantERA TAIOL
FIRB Futuro in Ricerca
2010 RBFR08H058_001
INFN Progetto Premiale
Atom Interferometer