Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum dissociation of a vortex-antivortex pair in a long Josephson
  junction   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.

36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th