Tuning the critical current in toroidal superfluids via controllable impurities

Year: 2026

Authors: Xhani K., Del Pace G., Grani N., Hernandez-Rajkov D., Donelli B., Roati G., Pezzè L.

Autors Affiliation: CNR, Ist Nazl Ott, Largo Enrico Fermi 6, I-50125 Florence, Italy; European Lab Nonlinear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Politecn Torino, Dept Appl Sci & Technol DISAT, I-10129 Turin, Italy; Natl Inst Metrol Res INRiM, Sesto Fiorentino Off LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; INFN, Sez Firenze, I-50019 Sesto Fiorentino, Italy.

Abstract: We combine numerical and experimental approaches to study how impurities affect the maximum superflow in an annular Bose-Einstein condensate. By tuning the impurity density and radial position, we precisely control persistent-current stability: it increases with the number of impurities and when impurities are placed at larger radii. In the unstable regime, the complex vortex motion within the impurity landscape, characterized by pinning and unpinning events, governs the timescale of the current decay and its final value. Our work establishes atomic superfluids as a pristine platform for exploring universal mechanisms of superflow stabilization and decay, paving the way for atomtronic quantum technologies.

Journal/Review: PHYSICAL REVIEW A

Volume: 113 (5)      Pages from: L051301-1  to: L051301-7

More Information: Acknowledgments. We thank Brynmor Haskell for fruitful discussions and Cyprien Daix for contributing to the initial experimental activity at an early stage of this work. K.X. acknowledges funding from the Italian MUR (PRIN DiQut Grant No. 2022523NA7). G.R. and G.D.P. acknowledge financial support from the PNRR MUR project PE0000023-NQSTI. G.R. acknowledges funding from the Italian Ministry of University and Research under the PRIN2017 project CEnTraL and project CNR-FOE-LENS-2024. The authors acknowledge support from the European Union, NextGen-erationEU, within the \u201CIntegrated Infrastructure Initiative in Photonics and Quantum Sciences\u201D (I-PHOQS). The authors acknowledge funding from INFN through the RELAQS project. This publication has received funding under the Horizon Europe programme HORIZON-CL4-2022-QUANTUM-02-SGA (project PASQuanS2.1, GA No. 101113690) and the Horizon 2020 research and innovation programme (GA No. 871124).
KeyWords: Anderson Localization; Superconductors; Vortices
DOI: 10.1103/316q-596d