Europhys. Lett.
Volume 67, Number 2, July 2004
Page(s) 273 - 279
Section Interdisciplinary physics and related areas of science and technology
Published online 01 July 2004
Europhys. Lett., 67 (2) , pp. 273-279 (2004)
DOI: 10.1209/epl/i2004-10065-1

Electric instability in superconductor-normal conductor ring

A. Kadigrobov

Theoretische Physik III, Ruhr-Universität Bochum - D-44801 Bochum, Germany

(Received 26 February 2004; accepted in final form 11 May 2004)

Non-linear electrodynamics of a ring-shaped Andreev interferometer (superconductor/normal conductor/superconductor hybrid structure) coupled to a circuit of the dissipative current is investigated. The current-voltage characteristics (CVC) is demonstrated to be a series of loops with several branches intersecting at the CVC origin. The sensitivity of the transport current $J_{\ab{d}}$ (or the applied voltage V) to a change of the external magnetic flux can be the same as the sensitivity of conventional SQUIDs. Spontaneous arising of coupled non-linear oscillations of the transport current, the Josephson current and the magnetic flux in Andreev interferometers are also predicted and investigated. The frequency of these oscillations can be varied in a wide range, while the maximal frequency can reach $\omega_{\max}\sim 10^{12}$ $\un{s^{-1}}$.

74.45.+c - Proximity effects; Andreev effect; SN and SNS junctions.
85.25.Dq - Superconducting quantum interference devices (SQUIDs).

© EDP Sciences 2004