Novel aspects of the Mott-Hubbard problem

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7241245

Zou, Z

The Mott-Hubbard problem has been almost the last hard well-posed problem of many-body theory in condensed matter physics. This was confirmed in January 1988, when it became clear that the high-T{sub c} superconductors are straightforward cases of the one-band Hubbard model. I summarize in this thesis some of the new development in dealing with the large-U Hubbard model, and present a basic formalism for the resonating-valence-bond (RVB) theory. After reviewing key experiments on high-T{sub c} superconductors, which invalidate the conventional fermi liquid theory, I derive an effective Hamiltonian and then proceed to perform mean field calculations. I explicitly show that there exists a local SU(2) invariance in the large-U Hubbard model. It follows from the gauge symmetry that various mean field theories at half filling are actually equivalent. I also go beyond the mean field approximation by studying phase fluctuations of the mean field order parameters with the help of gauge field theory. A connection is established between a fractional quantum Hall state and an RVB state on a square lattice. The RVB theory is then applied to explain experiments on high-T{sub c} superconductors, the transport experiments and normal tunneling in particular. The last chapter, somewhat isolated from the main body of the thesis, deals with the renormalized heavy fermion band formation in the presence of strong spin-orbit coupling.

• Research Organization: Princeton Univ., NJ (USA)
• OSTI ID: 7241245
• Country of Publication: United States
• Language: English

Related Subjects

656000* -- Condensed Matter Physics
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALCULATION METHODS
DATA ANALYSIS
MANY-BODY PROBLEM
MEAN-FIELD THEORY
PHYSICS
SOLID STATE PHYSICS
SUPERCONDUCTORS
SYMMETRY