Electronic behavior of highly correlated metals
This thesis addresses the question of the strongly interacting many-body problem: that is, systems where the interparticle correlations are so strong as to defy perturbative approaches. These subtle correlations occur in narrow band materials, such as the lanthanides and actinides, wherein the f-electrons are so localized that a variety of new phenomena, including intermediate-valence and heavy-fermionic behavior, may occur. As well, one has the alloying problem, where local interactions are paramount in determining the overall behavior. The technique employed in dealing with these systems is the Small Cluster method, wherein the full many-body Hamiltonian for a small grouping of atoms, coupled with periodic boundary conditions, is solved exactly. This is tantamount to solving a bulk crystal at the high points of symmetry in the Brillouin Zone. The mathematical overhead is further reduced by employing the full space group and spin symmetries. By its very nature, the Small Cluster method is well able to handle short-range interactions, as well as the combinatorial complexity of the many-body problem, on an equal footing. The nature of long-range order and phase transition behavior cannot be incorporated, but sometimes clues as to their origin can be discerned. The calculations presented include: a two-band Anderson model for an intermediate-valence system, wherein photoemission and fluctuation behavior is examined; a single-band Hubbard model for a ternary alloy system, such as copper-silver-gold; and a Hubbard model for a heavy- fermion system, wherein Fermi surface, transport, magnetic and superconducting properties are discussed. 148 refs., 31 figs., 24 tabs.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6985381
- Report Number(s):
- LBL-26091; ON: DE89002492
- Resource Relation:
- Other Information: Thesis (Ph.D.). Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
METALS
ELECTRONIC STRUCTURE
ALLOYS
BOUNDARY CONDITIONS
BRILLOUIN ZONES
CALCULATION METHODS
CORRELATIONS
CRYSTAL STRUCTURE
FERMIONS
FLUCTUATIONS
HAMILTONIANS
INTERATOMIC FORCES
MAGNETIC PROPERTIES
SOLID CLUSTERS
SUPERCONDUCTIVITY
TRANSPORT THEORY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
MATHEMATICAL OPERATORS
PHYSICAL PROPERTIES
QUANTUM OPERATORS
VARIATIONS
ZONES
656002* - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)
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