https://doi.org/10.1140/epjb/e2003-00205-5
Influence of temperature on the nodal properties of the longitudinal thermal conductivity of YBa2Cu3O7-x
Abteilung Supraleitung und Magnetismus, Institut für
Experimentelle Physik II, Universität Leipzig, Linnéstr. 5,
04103 Leipzig, Germany
Corresponding author: a esquin@physik.uni-leipzig.de
Received:
10
September
2002
Revised:
7
March
2003
Published online:
4
August
2003
The angle dependence at different temperatures of the longitudinal
thermal conductivity 
in the presence of a
planar magnetic field is presented. In order to study the
influence of the gap symmetry on the thermal transport, angular
scans were measured up to a few Kelvin below the critical
temperature Tc. We found that the four-fold oscillation of
vanishes at T > 20~K and transforms into a
one-fold oscillation with maximum conductivity for a field of 8 T
applied parallel to the heat current. Nevertheless, the results
indicate that the 
wave pairing symmetry remains the main
pairing symmetry of the order parameter up to Tc. Numerical
results of the thermal conductivity using an Andreev reflection
model for the scattering of quasiparticles by supercurrents under
the assumption of wave symmetry provide a semiquantitative
description of the overall results.
PACS: 74.25.Fy – Transport properties (electric and thermal conductivity, thermoelectric effects, etc.) / 74.72.Bk – Y-based cuprates / 72.15.-v – Electronic conduction in metals and alloys
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003
