Microcanonical finite-size scaling in second-order phase transitions with diverging specific heat.
Phys Rev E Stat Nonlin Soft Matter Phys
; 80(5 Pt 1): 051105, 2009 Nov.
Article
en En
| MEDLINE
| ID: mdl-20364945
ABSTRACT
A microcanonical finite-size ansatz in terms of quantities measurable in a finite lattice allows extending phenomenological renormalization (the so-called quotients method) to the microcanonical ensemble. The ansatz is tested numerically in two models where the canonical specific heat diverges at criticality, thus implying Fisher renormalization of the critical exponents the three-dimensional ferromagnetic Ising model and the two-dimensional four-state Potts model (where large logarithmic corrections are known to occur in the canonical ensemble). A recently proposed microcanonical cluster method allows simulating systems as large as L=1024 (Potts) or L=128 (Ising). The quotients method provides accurate determinations of the anomalous dimension, eta, and of the (Fisher-renormalized) thermal nu exponent. While in the Ising model the numerical agreement with our theoretical expectations is very good, in the Potts case, we need to carefully incorporate logarithmic corrections to the microcanonical ansatz in order to rationalize our data.
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Bases de datos:
MEDLINE
Asunto principal:
Modelos Químicos
Tipo de estudio:
Qualitative_research
Idioma:
En
Revista:
Phys Rev E Stat Nonlin Soft Matter Phys
Asunto de la revista:
BIOFISICA
/
FISIOLOGIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
España