Contact resistance and phase slips in mesoscopic superfluid-atom transport

Abstract

We have experimentally measured transport of superfluid, bosonic atoms in a mesoscopic system: a small channel connecting two large reservoirs. Starting far from equilibrium (superfluid in a single reservoir), we observe first resistive flow transitioning at a critical current into superflow, characterized by oscillations. We reproduce this full evolution with a simple electronic circuit model. We compare our fitted conductance to two different microscopic phenomenological models. We also show that the oscillations are consistent with LC oscillations as estimated by the kinetic inductance and effective capacitance in our system. Our experiment provides an attractive platform to begin to probe the mesoscopic transport properties of a dilute, superfluid, Bose gas.

Critical Transport and Vortex Dynamics in a Thin Atomic Josephson Junction

“…Re-cent experiments with inhomogeneous three-dimensional Fermi superfluids [24,25] revealed the intimate connection between phase slippage and dissipation arising from vortices created within the barrier and shed into the superfluid. Similar effects have been studied in ringshaped bosonic condensates [26][27][28][29], mesoscopic structures [30,31] and lower-dimensional geometries [32][33][34]. While vortices crossing the weak link are known to yield a finite resistance [25,27,30], the relation between microscopic vortex nucleation, dynamics and macroscopic dissipative flow is still poorly understood.…”

Einstein–Bose condensation of Onsager vortices

“…It seems that the most suitable system to study the critical physics of Einstein-Bose condensation of Onsager vortices is a single species vortex system. We therefore propose an experiment to observe condensates of Onsager vortices using a BEC or superfluid Fermi gas of atoms by creating a giant vortex with multiple circulation quanta using, e.g., topological phase imprinting [71] or high-winding number Laguerre-Gauss laser beams [72], to imprint a multiply quantised, N v ?2, quantum vortex into a superfluid in a preferably uniform trap [7,8,[26][27][28][29][30][31][32][33]. Subsequently monitoring the slow decay of the state into N v singly quantised vortices, evolving from configurations akin to figure 7(c) to those shown in (b), will enable quantitative observation of crossing the critical temperature T EBC .…”

Roadmap on structured light

“…produce double-well dumbbell potentials (analogous to an RLC circuit) [138]. Though amplitude based direct imaging methods are less commonly encountered in optical tweezers, the method of generalized phase contrast utilizes interference between a spatially configured phase pattern and reference beam to produce an intermediate amplitude pattern, subsequently reimaged to the trapping plane.…”