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 and dc bias current . 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 with and the crossover to the quantum regime at the temperature of about 100 mK.
Keywords
Cite
@article{arxiv.cond-mat/0307705,
title = {Quantum dissociation of a vortex-antivortex pair in a long Josephson junction},
author = {M. V. Fistul and A. Wallraff and Y. Koval and A. Lukashenko and B. A. Malomed and A. V. Ustinov},
journal= {arXiv preprint arXiv:cond-mat/0307705},
year = {2009}
}
Comments
4 pages, 3 figures