Stabilizing persistent currents in an atomtronic Josephson junction necklace
Year: 2024
Authors: Pezzè L., Xhani K., Daix C., Grani N., Donelli B., Scazza F., Hernandez-Rajkov D., Kwon WJ., Del Pace G., Roati G.
Autors Affiliation: Consiglio Nazl Ric CNR INO, Ist Nazl Ott, Largo Enrico Fermi 6, I-50125 Florence, Italy; European Lab Nonlinear Spect LENS, Via N Carrara 1, I-50019 Sesto Fiorentino, Italy; QSTAR, Largo Enrico Fermi 2, I-50125 Florence, Italy; Univ Florence, Phys Dept, Via Sansone 1, I-50019 Sesto Fiorentino, Italy; Univ Naples Federico II, Via Cinthia 21, I-80126 Naples, Italy; Univ Trieste, Phys Dept, Via A Valerio 2, I-34127 Trieste, Italy; Ulsan Natl Inst Sci & Technol UNIST, Phys Dept, Ulsan 44919, South Korea.
Abstract: Arrays of Josephson junctions are at the forefront of research on quantum circuitry for quantum computing, simulation, and metrology. They provide a testing bed for exploring a variety of fundamental physical effects where macroscopic phase coherence, nonlinearities, and dissipative mechanisms compete. Here we realize finite-circulation states in an atomtronic Josephson junction necklace, consisting of a tunable array of tunneling links in a ring-shaped superfluid. We study the stability diagram of the atomic flow by tuning both the circulation and the number of junctions. We predict theoretically and demonstrate experimentally that the atomic circuit withstands higher circulations (corresponding to higher critical currents) by increasing the number of Josephson links. The increased stability contrasts with the trend of the superfluid fraction – quantified by Leggett’s criterion – which instead decreases with the number of junctions and the corresponding density depletion. Our results demonstrate atomic superfluids in mesoscopic structured ring potentials as excellent candidates for atomtronics applications, with prospects towards the observation of non-trivial macroscopic superpositions of current states. Josephson junction arrays lead quantum circuitry research, vital for quantum computing, simulation, and metrology. Here the authors show that increasing the number of links in an atomtronic Josephson junction necklace enhances the atomic circuit’s resilience to higher circulations, corresponding to higher critical currents.
Journal/Review: NATURE COMMUNICATIONS
Volume: 15 (1) Pages from: 4831-1 to: 4831-8
More Information: We thank Massimo Inguscio, Giovanni Modugno, Augusto Smerzi and Andrea Trombettoni for discussions. L.P. and K.X. acknowledge financial support by the QuantEra project SQUEIS. C.D. acknowledges funding from project MUR FARE TOPSPACE. F.S. acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 949438) and from the Italian MUR under the FARE programme (project FastOrbit). G.R. acknowledges funding from the Italian Ministry of University and Research under the PRIN2017 project CEnTraL. G.R. and G.D.P. acknowledge financial support from the PNRR MUR project PE0000023-NQSTI. The Authors acknowledge support from the European Union – NextGenerationEU for the Integrated Infrastructure initiative in Photonics and Quantum Sciences – I-PHOQS [IR0000016, ID D2B8D520, CUP B53C22001750006]. This publication has received funding under Horizon Europe programme HORIZON-CL4-2022-QUANTUM-02-SGA via the project 101113690 (PASQuanS2.1)KeyWords: Superconducting Circuits; Quantum Interference; Locking; Arrays; SquidDOI: 10.1038/s41467-024-47759-7Citations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click here