Eur. Phys. J. B 44, 225-227 (2005)
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

Abstract

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.