Ratchet potential in d.c. SQUID's and reduced two-junction interferometer models
DIIMA University of Salerno, 84084 Fisciano (SA), Italy
Corresponding author: a firstname.lastname@example.org
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