Spin fluctuations and high temperature superconductivity in the copper oxides

The author reports studies of spin-fluctuation-induced superconductivity in the antiferromagnetically correlated copper oxide high temperature superconductors. The spin fluctuation mechanism is first studied within a weak coupling approximation. It is shown that the retarded interaction between quasiparticles on a 2D square lattice induced by the exchange of antiferromagnetic paramagnons leads uniquely to a transition to a superconducting state with dx2-y2 symmetry. The effective quasiparticle interaction responsible for superconductivity possesses considerable structure in both momentum and frequency space, and it is shown, by explicit calculations, that if one wishes to obtain quantitatively meaningful results it is essential to allow for that structure in solving the full integral equations which determine the superconducting transition temperature and the superconducting properties. With a spin excitation spectrum and a quasiparticle-paramagnon coupling determined by fits to normal state experiments, the author obtains high transition temperatures and energy gap behaviors comparable to those measured for YBa2Cu301, YBa2Cu306.63 , and Lai.ssSro.Is Cu04. The author then studies the influence of strong coupling effects, and high temperature superconductivity is obtained. This requires the solution of the Eliashberg equations taking full account of the momentum and frequency dependence of the effective interaction; approximations commonly used for phononinduced superconductivity fail to yield quantitatively meaningful results.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Monthoux, Philippe Henri

Contributors dc:contributor

• Pines, David

• spin-fluctuation-induced superconductivity
• spin fluctuations
• High Temperature Superconductivity
• copper oxide
• antiferromagnetically correlated copper oxide
• weak coupling approximation
• quasiparticles

Statement dc:rights

• 1992 Philippe Henri Monthoux

Language dc:language

en

Identifier

3471900

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/18884