October 2022

Abstract of the QSIT/Quantum Center, ETH Zurich Lunch Seminar, Thursday, October 6, 2022

Superfluid current through a dissipative quantum point contact

Jeffrey Mohan - Quantum Optics (Esslinger group), ETH Zurich

We measure superfluid transport of strongly-interacting fermionic lithium atoms through a quantum point contact with local, spin-dependent particle loss. We observe that the characteristic non-Ohmic superfluid transport enabled by high-order multiple Andreev reflections survives even at dissipation strength greater than the superfluid gap. We develop a model with mean-field reservoirs connected via tunneling to a dissipative site. Our calculations in the Keldysh formalism reproduce the observed non-equilibrium particle current, yet do not fully explain the observed loss rate or spin current.