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dc.contributor.advisorKirkpatrick, Theodore Ren_US
dc.contributor.authorZHOU, LUBOen_US
dc.date.accessioned2007-02-01T20:22:01Z
dc.date.available2007-02-01T20:22:01Z
dc.date.issued2006-11-24en_US
dc.identifier.urihttp://hdl.handle.net/1903/4136
dc.description.abstractIn this thesis a systematic, functional matrix field theory is developed to describe both clean and disordered s-wave and d-wave superconductors and the quantum phase transitions associated with them. The thesis can be divided into three parts. The first part includes chapters 1 to 3. In chapter one a general physical introduction is given. In chapters two and three the theory is developed and used to compute the equation of state as well as the number-density susceptibility, spin-density susceptibility, the sound attenuation coefficient, and the electrical conductivity in both clean and disordered s-wave superconductors. The second part includes chapter four. In this chapter we use the theory to describe the disorder-induced metal - superconductor quantum phase transition. The key physical idea here is that in addition to the superconducting order-parameter fluctuations, there are also additional soft fermionic fluctuations that are important at the transition. We develop a local field theory for the coupled fields describing superconducting and soft fermionic fluctuations. Using simple renormalization group and scaling ideas, we exactly determine the critical behavior at this quantum phase transition. Our theory justifies previous approaches. The third part includes chapter five. In this chapter we study the analogous quantum phase transition in disordered d-wave superconductors. This theory should be related to high $T_c$ superconductors. Surprisingly, we show that in both the underdoped and overdoped regions, the coupling of superconducting fluctuations to the soft disordered fermionic fluctuations is much weaker than that in the s-wave case. The net result is that the disordered quantum phase transition in this case is a strong coupling, or described by an infinite disordered fixed point, transition and cannot be described by the perturbative RG description that works so well in the s-wave case. The transition appears to be related to the one that occurs in disordered quantum antiferromagnets.en_US
dc.format.extent530037 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.titleMATRIX FIELD THEORY: APPLICATIONS TO SUPERCONDUCTIVITYen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentChemical Physicsen_US
dc.subject.pqcontrolledPhysics, Condensed Matteren_US


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