Fermions with tunable interactions... In the lithium lab we produce ultracold Fermi gases of 6Li to explore out-of-equilibrium dynamics and transport phenomena in strongly correlated fermionic matter. Atoms are confined into light-imprinted potential structures, simulating the motion of electrons in solid state devices. Our main goal is the study of two-dimensional strongly correlated phases, such as superfluidity across the BCS-BEC crossover and its robustness to disorder.

Observed the link between dissipative dynamics and phase slips in a fermionic Josephson junction

We study the emergence of dissipation in an atomic Josephson junction between weakly coupled superfluid Fermi gases. We find that vortex-induced phase slippage is the dominant microscopic source of dissipation across the BEC–BCS crossover. We explore different dynamical regimes by tuning the bias chemical potential between the two superfluid reservoirs. For small excitations, we observe dissipation and phase coherence to coexist, with a resistive current followed by well-defined Josephson oscillations. We link the junction transport properties to the phase-slippage mechanism, finding that vortex nucleation is primarily responsible for the observed trends of the conductance and critical current. For large excitations, we observe the irreversible loss of coherence between the two superfluids, and transport cannot be described only within an uncorrelated phase-slip picture. Our findings open new directions for investigating the interplay between dissipative and superfluid transport in strongly correlated Fermi systems, and general concepts in out-of-equilibrium quantum systems.

A. Burchianti, et al.,
Connecting Dissipation and Phase Slips in a Josephson Junction between Fermionic Superfluids
Phys. Rev. Lett. 120, 025302 (2018)

Li people

Alessandro Muzi Falconi
Master student
Giulia Del Pace
PhD student
Klejdja Xhani
Postdoctoral fellow
Woo Jin Kwon
Postdoctoral fellow
Francesco Scazza
Scientific staff
Massimo Inguscio
Scientific staff
Giacomo Roati
Scientific staff
Former members:
Andrea Amico
Alessia Burchianti
Chiara Fort
Riccardo Panza
Jorge Seman
Pedro Tavares
Giacomo Valtolina
Matteo Zaccanti

Li contacts

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

Giacomo Roati
(roati@lens.unifi.it)

Li funding

ERC CoG QUFERM2D
EU Quantum Flagship
Qombs (2018-2021)
PRIN 2017 CEnTraL
Progetto Ente Cassa QuSiM2D
H2020-MSCA-IF-2018 VorDIST
H2020-MSCA-IF-2015 SCOUTFermi2D