Nonlinear Effects in the Josephson Plasma Resonance

Abstract

Experimental and theoretical studies are reported of the stability of the zero-voltage state of Josephson tunnel junctions in the simultaneous presence of dc bias current and rf field at a frequency comparable to the Josephson plasma frequency. The observations can be qualitatively understood in terms of large amplitude parametric excitation of the plasma mode at fractional harmonics of the plasma frequency. The quasiparticle-pair interference or cos φ current appears to play a significant role in the observed phenomena. Comments are made on nonlinear phenomena in the longitudinal nuclear magnetic resonance in superfiuid 3 He A on the basis of a previously proposed analogy between the two systems. *The experimental work reported here was supported at the University of Pennsylvania by the Army Research Office (Durham) and the Advanced Research Projects Agency. Subsequent analysis by AJD was supported by the U. S. Atomic Energy Commission under Grant No. AT(11-1)-2027 and the National Science Foundation under Grant No. GH-40960, and by DNL by the Army Research Office (Durham) and the National Science Foundation. © 1975 Plenum Publishing Corporation, 227 West 17th Street, New York, N.Y. 10011. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission of the publisher.