https://doi.org/10.1140/epjb/e2005-00118-3
Ratchet potential in d.c. SQUID's and reduced two-junction interferometer models
DIIMA University of Salerno, 84084 Fisciano (SA), Italy
Corresponding author: a rdeluca@unisa.it
Received:
28
September
2004
Revised:
1
February
2005
Published online:
20
April
2005
For finite values of the parameter β and in the presence of small
structural asymmetry and inhomogeneity of the junctions parameters, the
two-junction interferometer model can be described by means of a single
non-linear differential equation in such a way that a ratchet potential for
SQUID's can be deduced. The resulting dynamical equation, derived for
first-order corrections with respect to a symmetric and homogeneous model
with 
, presents an additional second-harmonic term and a cosine
term in the expression for the effective current-phase relation. For
opportune values of the perturbation parameters a ratchet potential with
pre-definite characteristics can be obtained.
PACS: 74.50.+r – Tunneling phenomena; point contacts, weak links, Josephson effects / 85.25.Dq – Superconducting quantum interference devices (SQUIDs)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
