Quantum dissociation of a vortex-antivortex pair in a long Josephson junction

Abstract

We report a theoretical analysis and experimental observation of the quantum dynamics of a single vortex-antivortex (VAV) pair confined in a long narrow annular Josephson junction. The switching of the junction from the superconducting state to the resistive state occurs via the dissociation of a pinned VAV pair. The pinning potential is controlled by external magnetic field $H$ and dc bias current $I$. We predict a specific magnetic field dependence of the oscillatory energy levels of the pinned VAV state and the crossover to a {\it macroscopic quantum tunneling} mechanism of VAV dissociation at low temperatures. Our analysis explains the experimentally observed {\it increase} of the width of the switching current distribution $P(I)$ with $H$ and the crossover to the quantum regime at the temperature of about 100 mK.

arXiv comment4 pages, 3 figures

References in corpus (4)

• Multi-photon transitions between energy levels in a current-biased Josephson tunnel junction
• High resolution measurements of the switching current in a Josephson tunnel junction: Thermal activation and macroscopic quantum tunneling
• Macroscopic Quantum Tunneling of a Fluxon in a Long Josephson Junction
• Dimensional Crossover by a Local Inhomogeneity in Soliton-Pair Nucleation

Cited by in corpus (8)

• Vortex-antivortex nucleation in magnetically nanotextured superconductors: Magnetic-field-driven and thermal scenarios
• Spectroscopy and Directed Transport of Topological Solitons in Crystals of Trapped Ions
• Tunneling of persistent currents in coupled ring-shaped Bose-Einstein condensates
• Observation of a New Fluxon Resonant Mechanism in Annular Josephson Tunnel Structures
• Quantum beats of a magnetic fluxon in a two-cell SQUID
• Generation of slow intense optical solitons in a resonance photonic crystal
• Quantum dynamics of a $4\pi$-kink in Josephson junctions parallel arrays with large kinetic inductances
• Influence of length on the noise delayed switching of long Josephson junctions