Eur. Phys. J. B 32, 437-444 (2003)
https://doi.org/10.1140/epjb/e2003-00125-4

Observation of a sharp lambda peak in the third harmonic voltage response of high-T_c superconductor thin films^*

¹ Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
² Department of Theoretical Physics, Sofia University St. Kliment Ohridski, 5 J. Bourchier Blvd., 1164 Sofia, Bulgaria

Corresponding author: ^a joseph.indekeu@fys.kuleuven.ac.be

Received: 13 November 2002
Revised: 21 February 2003
Published online: 7 May 2003

Abstract

In this paper, we report on the sharp peak observed in the third harmonic voltage response generated by a bias sinusoidal current applied to several strips patterned in a YBa₂Cu₃O thin film and in two LaSr_xCuO₄ thin films, when the temperature is close to the normal-superconductor transition. The lambda-shaped temperature dependence of the third harmonic signal on the current characteristics is studied. Several physical mechanisms of third harmonic generation are examined.