Criticality and conformality in the random dimer model
Abstract
In critical systems, the effect of a localized perturbation affects points that are arbitrarily far from the perturbation location. In this paper, we study the effect of localized perturbations on the solution of the random dimer problem in two dimensions. By means of an accurate numerical analysis, we show that a local perturbation of the optimal covering induces an excitation whose size is extensive with finite probability. We compute the fractal dimension of the excitations and scaling exponents. In particular, excitations in random dimer problems on nonbipartite lattices have the same statistical properties of domain walls in spin glass. Excitations produced in bipartite lattices, instead, are compatible with a looperased selfavoiding random walk process. In both cases, we find evidence of conformal invariance of the excitations that is compatible with SLE_{κ} with parameter κ depending on the bipartiteness of the underlying lattice only.
 Publication:

Physical Review E
 Pub Date:
 April 2021
 DOI:
 10.1103/PhysRevE.103.042127
 arXiv:
 arXiv:2012.13956
 Bibcode:
 2021PhRvE.103d2127C
 Keywords:

 Condensed Matter  Disordered Systems and Neural Networks;
 Mathematical Physics
 EPrint:
 8 pages