Probing superfluidity with quantum vortex necklaces and Leggett's bounds

We theoretically investigate a binary Bose-Einstein condensate in which the majority component hosts a vortex necklace, whose vortex cores act as moving effective potential wells for the minority component. This configuration represents a tunable periodic landscape whose strength is controlled by th...

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Bibliographic Details
Authors: Richaud, Andrea|||0000-0001-8940-6936, Massignan, Pietro Alberto|||0000-0003-1545-792X
Format: article
Publication Date:2025
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/450722
Online Access:https://hdl.handle.net/2117/450722
https://dx.doi.org/10.1103/r5x2-yy6v
Access Level:Open access
Keyword:Bose-Bose mixtures
Mott-superfluid transition
Vortices in superfluids
Superfluids
Àrees temàtiques de la UPC::Física::Física de fluids
Description
Summary:We theoretically investigate a binary Bose-Einstein condensate in which the majority component hosts a vortex necklace, whose vortex cores act as moving effective potential wells for the minority component. This configuration represents a tunable periodic landscape whose strength is controlled by the intercomponent interaction. As the coupling increases, the minority component undergoes a crossover from a delocalized, nearly perfect superfluid to an array of localized density peaks confined within the vortex cores. Using Gross-Pitaevskii simulations, we compute the moment of inertia of the minority component and show that its superfluid fraction is tightly bracketed by Leggett's bounds constructed from its density profile. Because these bounds depend solely on the spatial density distribution, they may be extracted directly from experimentally accessible measurements. Our results identify vortex necklaces as a controllable tool for tuning and probing superfluidity in two-component condensates and provide a natural framework for exploring superfluid behavior in dynamically evolving and disordered potentials.