Experimental determination of the symmetry of the superconducting pairing state in yttrium barium copper oxide

In this thesis I present measurements of bimetallic Pb-Au-YBCO dc SQUIDs (Superconducting QUantum Interference Devices) and Josephson junctions that provide an important clue to the origin of the pairing mechanism for high temperature superconductivity in the cuprates. By probing the momentum space anisotropy of the phase of the superconducting order parameter, we can experimentally determine the symmetry of the superconducting pairing state in YBCO and distinguish between the leading candidate states that have been proposed. We find that the superconducting order parameter in YBCO changes sign between orthogonal directions in momentum space, unlike the isotropic order parameter in conventional superconductors. The sign change of the order parameter is consistent with a $d\sb{x\sp2-y\sp2}$ pairing state symmetry.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Wollman, David Anders

Contributors dc:contributor

• Greene, Laura H.

• Physics, Condensed Matter

Statement dc:rights

• Copyright 1996 Wollman, David Anders

Language dc:language

eng

Identifier

AAI9625215
(UMI)AAI9625215

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20693