We have used thermal conductivity measurements at low temperature to probe the behavior of the unconventional superconductor YBa2Cu 3O7-delta (YBCO). Two aspects were investigated: (1) the in-plane anisotropy, studied in order to gain insight into the contribution of CuO chains, and (2) the effect of a magnetic field, investigated in order to explore the contribution of vortices. Our results on the low temperature thermal conductivity are in good quantitative agreement with the theory for a d-wave superconductor. We have found a very weak (or even negligible) anisotropy suggesting that the anisotropy could not simply be explained by mass tensor anisotropy or the plasma frequency anisotropy. The magnetic field studies revealed an increase in the residual linear term (kappa/ T as T → 0) with field, reflecting the contribution to the density of states from the extended quasiparticles due to their Doppler shift in the presence of vortices. These results are in good quantitative agreement with the theoretical predictions.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.21625 |
| Date | January 1998 |
| Creators | Popić, Bojana. |
| Contributors | Taillefer, Louis (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001657575, proquestno: MQ50858, Theses scanned by UMI/ProQuest. |
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