The Josephson effect is a macroscopic quantum phenomenon that reveals the broken symmetry associated with any superfluid state. Here we report on the observation of the Josephson effect between two fermionic superfluids coupled through a thin tunneling barrier. We show that the relative population and phase are canonically conjugate dynamical variables throughout the crossover from the molecular Bose-Einstein condensate (BEC) to the Bardeen-Cooper-Schrieffer (BCS) superfluid regime. For larger initial excitations from equilibrium, the dynamics of the superfluids become dissipative, which we ascribe to the propagation of vortices through the superfluid bulk. Our results highlight the robust nature of resonant superfluids.
Josephson effect in fermionic superfluids across the BEC-BCS crossover / Valtolina, Giacomo; Burchianti, Alessia; Amico, Andrea; Neri, Elettra; Xhani, Klejdja; Seman, Jorge Amin; Trombettoni, Andrea; Smerzi, Augusto; Zaccanti, Matteo; Inguscio, Massimo; Roati, Giacomo. - In: SCIENCE. - ISSN 0036-8075. - STAMPA. - 350:(2015), pp. 1505-1508. [10.1126/science.aac9725]
Josephson effect in fermionic superfluids across the BEC-BCS crossover
AMICO, ANDREA;NERI, ELETTRA;SMERZI, AUGUSTO;ZACCANTI, MATTEO;INGUSCIO, MASSIMO;ROATI, GIACOMO
2015
Abstract
The Josephson effect is a macroscopic quantum phenomenon that reveals the broken symmetry associated with any superfluid state. Here we report on the observation of the Josephson effect between two fermionic superfluids coupled through a thin tunneling barrier. We show that the relative population and phase are canonically conjugate dynamical variables throughout the crossover from the molecular Bose-Einstein condensate (BEC) to the Bardeen-Cooper-Schrieffer (BCS) superfluid regime. For larger initial excitations from equilibrium, the dynamics of the superfluids become dissipative, which we ascribe to the propagation of vortices through the superfluid bulk. Our results highlight the robust nature of resonant superfluids.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.