Decay of persistent currents in annular atomic superfluids

Abstract

We investigate the role of vortices in the decay of persistent current states of annular atomic superfluids by solving numerically the Gross-Pitaevskii equation, and we directly compare our results with experimental data from Ref. [1]. We theoretically model the optical phase-imprinting technique employed to experimentally excite finite-circulation states in Ref. [1] in the Bose-Einstein condensation regime, accounting for imperfections of the optical gradient imprinting profile. By comparing simulations of this realistic protocol to an ideal imprinting, we show that the introduced density excitations arising from imperfect imprinting are mainly responsible for limiting the maximum reachable winding number $w_{\max }$ in the superfluid ring. We also investigate the effect of a point-like obstacle with variable potential height $V_0$ onto the decay of circulating supercurrents. For a given obstacle height, a critical circulation $w_c$ exists, such that for an initial circulation $w_0$ larger than $w_c$ the supercurrent decays through the emission of vortices, which cross the superflow and thus induce phase slippage. Higher values of the obstacle height $V_0$ further favour the entrance of vortices, thus leading to lower values of $w_c$. Furthermore, the stronger vortex-defect interaction at higher $V_0$ leads to vortices that propagate closer to the center of the ring condensate. The combination of both these effects leads to an increase of the supercurrent decay rate for increasing $w_0$, in agreement with experimental observations. [1]: G. Del Pace, et al., Phys. Rev. X 12, 041037 (2022)

References in corpus (23)

• Watching dark solitons decay into vortex rings in a Bose-Einstein condensate
• Observation of persistent flow of a Bose-Einstein condensate in a toroidal trap
• Superflow in a toroidal Bose-Einstein condensate: an atom circuit with a tunable weak link
• Hysteresis in a quantized, superfluid atomtronic circuit
• Driving phase slips in a superfluid atom circuit with a rotating weak link
• Quantised supercurrent decay in an annular Bose-Einstein condensate
• Persistent currents in normal metal rings
• Quench-induced supercurrents in an annular Bose gas
• Persistent currents in spinor condensates
• Roadmap on Atomtronics: State of the art and perspective
• Observation of Solitonic Vortices in Bose-Einstein Condensates
• Atomtronic circuits: from many-body physics to quantum technologies
• Superfluidity and Swallowtails; Hysteretic Behavior in Bose Condensates
• From Planar Solitons to Vortex Rings and Lines: Cascade of Solitonic Excitations in a Superfluid Fermi Gas
• Imprinting persistent currents in tunable fermionic rings
• Persistent currents in rings of ultracold fermionic atoms
• Producing superfluid circulation states using phase imprinting
• Critical transport and vortex dynamics in a thin atomic Josephson junction
• Persistent currents with non-quantized angular momentum
• Snake instability of dark solitons in fermionic superfluids
• Oscillations and decay of superfluid currents in a one-dimensional Bose gas on a ring
• Self-heterodyne detection of the {\it in-situ} phase of an atomic-SQUID
• Temperature induced decay of persistent currents in a superfluid ultracold gas

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• Conformal maps and superfluid vortex dynamics on curved and bounded surfaces: the case of an elliptical boundary
• Density Modulations of Zero Sound
• Impurity-controlled vortex mobility and pair-breaking in fermionic superfluid rings
• Controlled acoustic-driven vortex transport in coupled superfluid rings
• Dynamically generating superflow in a bosonic ring via phase imprinting