Renormalized (1/σ) Expansion for Lattice Animals and Localization

Loading...
Thumbnail Image
Penn collection
Department of Physics Papers
Degree type
Discipline
Subject
Physics
Funder
Grant number
License
Copyright date
Distributor
Related resources
Contributor
Abstract

The use of the (1/σ) expansion to calculate the thermodynamic properties of systems such as the Ising model or percolation whose diagrammatic expansion contains only diagrams with no free ends is reviewed. Here σ=z−1, where z is the coordination number of the lattice. For more general problems we formulate a self-consistency condition for a site potential h, so that diagrams with free ends are eliminated. Construction of h gives the leading order in (1/σ) solution and is exact for the Cayley tree. We obtain correction terms by using a bond renormalized interaction so that to order (1/σ)5 we need only consider two-site problems. Results are given for (1) Kc, the critical fugacity for animals, when either H, the fugacity for free ends, or Q, the density of free ends, is fixed, and (2) (t/Ec), where Ec is the mobility energy and t is the magnitude of the hopping matrix element whose sign is random. At d=8 our results appear to be accurate to within about 0.01% for both animals and localization. We also obtain an expansion for Q(Kc)/(zKc) whose divergence near spatial dimensionality d=4 supports the idea that the order-parameter exponent β for lattice animals passes through zero at d=4.

Advisor
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Publication date
1982-07-01
Journal title
Physical Review B
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
Recommended citation
Collection