arXiv:2411.09186 · Physical Review A

Acceleration-driven dynamics of Josephson vortices in coplanar superfluid rings

Yurii Borysenko, Nataliia Bazhan, O. O. Prikhodko, Dominik Pfeiffer, Ludwig Lind, G. Birkl, A. I. Yakimenko

Published Apr 14, 2025• 4 citations

Abstract

Precise control of topologically protected excitations, such as quantum vortices in atomtronic circuits, opens new possibilities for future quantum technologies. We theoretically investigate the dynamics of Josephson vortices (rotational fluxons) induced by coupled persistent currents in a system of coplanar double-ring atomic Bose-Einstein condensates. We study the Josephson effect in an atomic Josephson junction formed by coaxial ring-shaped condensates. Tunneling superflows, initiated by an imbalance in atomic populations between the rings, are significantly influenced by the persistent currents in the inner and outer rings. This results in pronounced Josephson oscillations in the population imbalance for both corotating and nonrotating states. If a linear acceleration is applied to the system, our analysis reveals peculiar azimuthal tunneling patterns and dynamics of Josephson vortices which leads to nonzero net tunneling current and shows sensitivity to the acceleration magnitude. When multiple Josephson vortices are present, asymmetric vortex displacements that correlate with both the magnitude and direction of acceleration can be measured, offering the potential for quantum sensing applications.

DOI: 10.1103/physreva.111.043308

Related papers

Tunneling of persistent currents in coupled ring-shaped Bose–Einstein condensates

Artem Oliinyk, A. I. Yakimenko, Boris A. Malomed

Abstract Considerable progress in experimental studies of atomic gases in a toroidal geometry opens up novel prospects for the investigation of fundamental properties of superfluid states and creation of new configurations for atomtronic circuits. In particular, a setting with Bose–Einstein condensates loaded in a dual-ring trap suggests a possibility to consider the dynamics of tunneling between condensates with different angular momenta. Accordingly, we address the tunneling in a pair of coaxial three-dimensional (3D) ring-shaped condensates separated by a horizontal potential barrier. A truncated (finite-mode) Galerkin model and direct simulations of the underlying 3D Gross–Pitaevskii equation are used for the analysis of tunneling superflows driven by an initial imbalance in atomic populations of the rings. The superflows through the corresponding Bose–Josephson junction are strongly affected by persistent currents in the parallel rings. Josephson oscillations of the population imbalance and angular momenta in the rings are obtained for co-rotating states and non-rotating ones. On the other hand, the azimuthal structure of the tunneling flow demonstrates formation of Josephson vortices (fluxons) with zero net current through the junction for hybrid states , built of counter-rotating persistent currents in the coupled rings.

arXiv:1901.06502Journal of Physics B Atomic Molecular and Optical PhysicsSep 23, 201924 citations

Acceleration-induced transport of quantum vortices in joined atomtronic circuits

Andrii Chaika, Artem Oliinyk, I. V. Yatsuta +4 more

Persistent currents–inviscid quantized flow around an atomic circuit–are a crucial building block of atomtronic devices. We investigate how acceleration influences the transfer of persistent currents between two density-connected, ring-shaped atomic Bose-Einstein condensates, joined by a tunable weak link that controls system topology. We find that the acceleration of this system modifies both the density and phase dynamics between the rings, leading to a bias in the periodic vortex oscillations studied in T. Bland et al., Phys. Rev. Research 4, 043171 (2022). Accounting for dissipation suppressing such vortex oscillations, the acceleration facilitates a unilateral vortex transfer to the leading ring. We analyze how this transfer depends on the weak-link amplitude, the initial persistent current configuration, and the acceleration strength and direction. Characterization of the sensitivity to these parameters paves the way for a new platform for acceleration measurements, for which we outline a proof-of-concept ultracold double-ring accelerometer.

arXiv:2410.23818SciPost PhysicsJul 2, 20254 citations

Generation of Josephson vortices in stacked toroidal Bose-Einstein condensates

Nataliia Bazhan, Anton Svetlichnyi, Dominik Pfeiffer +3 more

Coupled coaxially stacked toroidal condensates with persistent currents suggest an appealing physical platform for investigation of various phenomena related to interacting superflows from Josephson effects in the regime of weak interactions to the quantum Kelvin-Helmholtz instability for merging rings. We suggest experimentally accessible methods to prepare states with different topological charges in two coupled coaxial ring-shaped atomic Bose-Einstein condensates. Our results open up the way to direct observation of rotational Josephson vortices in atomic Bose-Einstein condensates.

arXiv:2204.14269Physical Review AOct 10, 202217 citations

Spinor condensate persistent currents in an atomtronic Josephson necklace

Sayan Chatterjee, N. Pradhan, Rina Kanamoto +2 more

The investigation of superflow in multi-junction Josephson circuits is currently a leading frontier of physics research, probing the fundamental manifestations of macroscopic phase coherence and enabling applications to quantum simulation, metrology and computing. In this work, we extensively investigate the stability and dynamics of persistent currents of a spinor atomic Bose-Einstein condensate on a ring with multiple Josephson junctions. Specifically, we examine the effects of positive and negative interspecies interactions, co- and counter-rotation, population and Manakov asymmetry, as well as Rabi coupling on the persistent currents carried by the two components. Our analysis reveals that the presence of a second species offers multiple mechanisms for unprecedented manipulation of supercurrents on the ring, including phase-slip engineering, stability control, current-inversion switching and supercurrent pumping. Our study provides a roadmap for the engineering of persistent currents in binary ring condensates in necklace potentials, with significant implications for atomtronics, matter-wave interferometry and sensing using atomic Bose gases.

arXiv:2608.23560Aug 24, 20260 citations

Bose-Einstein condensates in coupled co-planar double-ring traps : a thesis presented in partial fulfillment of the requirements for the degree of Masterate of Science in Physics at Massey University, Palmerston North, New Zealand

Tania J. Haigh

This thesis presents a theoretical study of Bose-Einstein condensates in a doublering trap. In particular, we determine the ground states of the condensate in the double-ring trap that arise from the interplay of quantum tunnelling and the trap’s rotation. The trap geometry is a concentric ring system, where the inner ring is of smaller radius than the outer ring and both lie in the same two-dimensional plane. Due to the difference in radii between the inner and outer rings, the angular momentum that minimises the kinetic energy of a condensate when confined in the individual rings is different at most frequencies. This preference is in direct competition with the tunnel coupling of the rings which favours the same angular momentum states being occupied in both rings. Our calculations show that at low tunnel coupling ground state solutions exist where the expectation value of angular momentum per atom in each ring differs by approximately an integer multiple. The energy of these solutions is minimised by maintaining a uniform phase difference around most of the ring, and introducing a Josephson vortex between the inner and outer rings. A Josephson vortex is identified by a 2p step in the relative phase between the two rings, and accounts for one quantum of circulation. We discuss similarities and differences between Josephson vortices in cold-atom systems and in superconducting Josephson junctions. Josephson vortices are actuated by a sudden change in the trapping potential. After this change Josephson vortices rotate around the double-ring system at a different frequency to the rotation of the double-ring potential. Numerical studies of the dependence of the velocity on the ground state tunnel coupling and interaction strength are presented. An analytical theory of the Josephson vortex dynamics is also presented which is consistent with our numerical results.

Jan 1, 20080 citations

Josephson vortices and persistent current in a double-ring supersolid system

M. Schubert, K. Mukherjee, Tilman Pfau +1 more

We theoretically investigate the properties of ultracold dipolar atoms in radially coupled, concentric annular traps created by a potential barrier. The nonrotating ground-state phases are investigated across the superfluid-supersolid phase transition, revealing a particle imbalance between the two rings and a preferential density modulation in the outer ring in the absence of rotation. Near the phase transition on the superfluid side, applying rotation can induce density modulations in either ring, depending on the angular momentum and barrier strength. For low angular momentum, such rotation-induced density modulation forms in the outer ring, while for high angular momentum and weak barriers, it emerges in the inner ring. Rotation can lead to persistent currents and the nucleation of a vortex residing either at the center (central vortex) or at the ring junction (Josephson vortex). Josephson vortices can also form at the junctions of the localized density sites induced by rotation in the inner ring, a behavior that is unique to our system. By switching off the trap and allowing the system to expand, distinct interference patterns emerge, which can be analyzed to identify and distinguish between various vortex configurations, and thus can be observed in current state-of-the-art experiments.

arXiv:2503.11212Physical Review ResearchJun 23, 20255 citations