Connecting dissipation and phase slips in a Josephson junction between fermionic superfluids
arXiv:1707.02784 · doi:10.1103/PhysRevLett.120.025302
Abstract
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 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-equlibrium quantum systems.
6 pages, 4 figures + Supplemental Material
References in corpus (13)
- Critical velocity for superfluid flow across the BEC-BCS crossover
- Observing the Drop of Resistance in the Flow of a Superfluid Fermi Gas
- The critical velocity in the BEC-BCS crossover
- Efficient all-optical production of large Li quantum gases using D gray-molasses cooling
- BEC-BCS crossover and universal relations in unitary Fermi gases
- Phase-slip induced dissipation in an atomic Bose-Hubbard system
- The Josephson effect throughout the BCS-BEC crossover
- Sound propagation in elongated superfluid fermion clouds
- Critical velocity of superfluid flow through single barrier and periodic potentials
- The Landau critical velocity for a particle in a Fermi superfluid
- Phase-slips and vortex dynamics in Josephson oscillations between Bose-Einstein condensates
- Towards Quantum Turbulence in Cold Atomic Fermionic Superfluids
- Fluctuation Effects on the Transport Properties of Unitary Fermi Gases