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Thermal conductivity tensor inYBa2Cu3O7−Ocaña1, Esquinazi2 2002Phys. Rev. B272390View full textAdd to dashboardCite

“…18,19 With polarized light microscopy we have determined the positions of the twinning planes. Accordingly, the heat current direction was adjusted along the a/b axes which were parallel to the width or length of the sample.…”

“…Up to now, however, there is not enough experimental evidence for such a state, although results on the magnetic-field dependence of the longitudinal thermal conductivity in Bi 2 Sr 2 CaCu 2 O 8 ͑BSCCO͒ ͑Refs. 17 and 18͒ and temperature dependence of the Hall angle 19 could be explained by taking into account the violation of both parity and time-reversal symmetry. In this paper we recover this idea and attempt to establish the highest value, if any, for a component id xy of the superconducting order parameter within the current models for the thermal transport in the HTS cuprates.…”

Angle Dependence of the Transverse Thermal Conductivity inYBa2Cu3O7Singl

“…Nowadays there is consent that k xy is a suitable property to check theoretical expressions of electronic thermal transport since it is free from nonelectronic contributions. In this Letter we report on the magnetic field B, field angle u, and temperature T dependence of k xy for fields applied parallel to the CuO 2 planes.The magnetic field, field angle, and temperature dependence of k xy were studied on two Y123 single crystals.One sample was an optimally doped twinned single crystal with dimensions (length 3 width 3 thickness) 0.83 3 0.6 3 0.045 mm 3 and critical temperature T c 93.4 K [11,12]. The second sample was an untwinned Y123 single crystal with dimensions 2.02 3 0.68 3 0.14 mm 3 and T c 88 K. The heat current J was along the longest axis of the crystal [in case of the untwinned (twinned) crystal it was parallel to its a axis (a͞b axes)].…”

“…One sample was an optimally doped twinned single crystal with dimensions (length 3 width 3 thickness) 0.83 3 0.6 3 0.045 mm 3 and critical temperature T c 93.4 K [11,12]. The second sample was an untwinned Y123 single crystal with dimensions 2.02 3 0.68 3 0.14 mm 3 and T c 88 K. The heat current J was along the longest axis of the crystal [in case of the untwinned (twinned) crystal it was parallel to its a axis (a͞b axes)].…”

“…In this equation we used the experimental fact that the oscillation amplitude of the longitudinal component of the thermal conductivity k xx -which has been shown to have fourfold symmetry at T͞T c , 0.26 [10]-is much smaller than the longitudinal temperature gradient j= x T j [13]. Therefore k xy shows the same field-angle dependence as = y T. The longitudinal and transverse temperature gradients were measured using a previously field-and temperaturecalibrated type E thermocouple with a dc picovoltmeter [14].…”