Fermions with tunable interactions... In the Lithium lab we produce binary mixtures of 6Li Fermi gases to investigate fermionic superfluidity across the BEC-BCS crossover. Our main goal is to study two-dimensional fermionic superfluids.

Ferromagnetic behaviour of a repulsive Fermi gas

We study the collective spin response and spin diffusion of an ultracold lithium Fermi gas artificially engineered in a fully ferromagnetic state, obtained by spatially segregating oppositely-oriented spins into two adjacent reservoirs. In this way, we show that strong repulsive interactions are sufficient to temporarily stabilize ferromagnetic correlations in a Fermi mixture. In particular, we reveal a substantial increase of the magnetic susceptibility of the gas while approaching the critical value of interaction. Correspondingly, we show that above the critical interaction a spin up-down domain wall can persist for a finite time, indicating the metastability of the ferromagnetic state. Such findings point to Stoner-like ferromagnetic instability driven only by short-range repulsion, and are consistent with our recent study of a repulsive Fermi liquid of polarons in strongly polarized Fermi gases.

G. Valtolina, et al.,
Exploring the ferromagnetic behaviour of a repulsive Fermi gas through spin dynamics
Nat. Phys. 13, 704 (2017)

Li people

Riccardo Panza
Master student
Giulia Del Pace
PhD student
Andrea Amico
PhD student
Woo-Jin Kwon
Research fellow
Francesco Scazza
Research fellow
Matteo Zaccanti
Permanent researcher
Massimo Inguscio
Permanent researcher
Giacomo Roati
Permanent researcher
Former members:
Alessia Burchianti
Chiara Fort
Jorge Seman
Pedro Tavares
Giacomo Valtolina

Li contacts

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

Giacomo Roati
(roati@lens.unifi.it)

Li funding