Low-field magnetic response of multi-junction superconducting quantum interference devices
DMI, Università degli Studi di Salerno, Via Ponte Don Melillo, 84084 Fisciano (SA), Italy
Corresponding author: a firstname.lastname@example.org
Published online: 31 January 2008
The magnetic states of multi-junction superconducting quantum interference device containing 2N identical conventional Josephson junctions are studied by means of a perturbation analysis of the non-linear first-order ordinary differential equations governing the dynamics of the Josephson junctions in these devices. In the zero-voltage state, persistent currents are calculated in terms of the externally applied magnetic flux Φex . The resulting d.c. susceptibility curves show that paramagnetic and diamagnetic states are present, depending on the value of Φex . The stability of these states is qualitatively studied by means of the effective potential notion for the system.
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, 2008