Volume 77, Number 2, January 2007
Article Number 27002
Number of page(s) 4
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 05 January 2007
EPL, 77 (2007) 27002
DOI: 10.1209/0295-5075/77/27002

Mixed order parameter symmetries in cuprate superconductors

A. Bussmann-Holder1, R. Khasanov2, A. Shengelaya3, A. Maisuradze2, F. La Mattina2, H. Keller2 and K. A. Müller2

1  Max-Planck-Institut für Festkörperforschung - Heisenbergstrasse 1, D-70569 Stuttgart, Germany
2  Physik Institut der Universität Zürich - Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
3  Physics Institute of Tbilisi State University - Chavchadze 3, GE-0128 Tbilisi, Georgia

received 17 August 2006; accepted in final form 16 November 2006; published January 2007
published online 5 January 2007

The recent observation of an inflection point in the temperature dependence of the in-plane magnetic field dependence $(\lambda _{{\rm ab}})$ is investigated within a two-band model with coupled order parameters of different symmetries. While the dominant order parameter has d-wave symmetry, the smaller one is of s-wave symmetry. Superconductivity is robust in the d-wave channel and induced via interband interactions in the s-wave subsystem.

74.20.-z - Theories and models of superconducting state .
74.72.-h - Cuprate superconductors (high-Tc and insulating parent compounds).
74.20.Rp - Pairing symmetries (other than s-wave) .

© Europhysics Letters Association 2007