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Quantum critical phenomena in superfluids and superconductors

Citation

Kim, Kihong (1991) Quantum critical phenomena in superfluids and superconductors. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-06222007-140913

Abstract

We discuss some problems related to quantum critical phenomena in superfluids and superconductors.

In Ch. 1, we apply generalizations of hyperuniversality to quantum phase transitions at zero temperature. We find new universal amplitude combinations involving the superfluid density in Bose systems, as well as confirm and extend previous proposals for universal transport coefficients in two-dimensional superconducting films and magnetic-field-induced metal-insulator transitions.

In Ch. 2, we apply the double-dimensionality expansion of Dorogovstev to derive renormalization-group recursion relations for a Bose fluid in a random external potential. We find a nontrivial fixed point. The onset of mean-field behavior for dimensions d > d[subscript]c = 4 is unconventional, yielding discontinuous exponents. Including positive temperatures, we give a clear picture of various crossover regimes.

In Ch. 3, We give a detailed derivation of the critical thermodynamics of O(n) spin models, correct to O([epsilon] = 4 - d), using a generalization of the renormalization-group trajectory integral and noncritical matching technique introduced by Rudnick and Nelson. We especially emphasize the coexistence-curve behavior for spins with a continuous symmetry (n [...] 2), deriving detailed expressions for the renormalized spin-wave stiffness and longitudinal susceptibility.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Restricted to Caltech community only
Research Advisor(s):
  • Cross, Michael Clifford
Thesis Committee:
  • Unknown, Unknown
Defense Date:21 May 1991
Record Number:CaltechETD:etd-06222007-140913
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-06222007-140913
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2691
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:18 Jul 2007
Last Modified:26 Dec 2012 02:53

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