Classical correlationlength exponent in the nonuniversal quantum phase transition of a diluted Heisenberg antiferromagnet
Abstract
Critical behavior of the quantum phase transition of a sitediluted Heisenberg antiferromagnet on a square lattice is investigated by means of the quantum Monte Carlo simulation with the continuousimaginarytime loop algorithm. Although the staggered spincorrelation function decays in a power law with the exponent definitely depending on the spin size S, the correlationlength exponent is classical, i.e., ν=4/3. This implies that the length scale characterizing the nonuniversal quantum phase transition is nothing but the mean size of connected spin clusters.
 Publication:

Physical Review B
 Pub Date:
 April 2001
 DOI:
 10.1103/PhysRevB.63.140415
 arXiv:
 arXiv:condmat/0010397
 Bibcode:
 2001PhRvB..63n0415Y
 Keywords:

 75.10.Jm;
 75.10.Nr;
 75.40.Cx;
 75.40.Mg;
 Quantized spin models;
 Spinglass and other random models;
 Static properties;
 Numerical simulation studies;
 Condensed Matter  Disordered Systems and Neural Networks
 EPrint:
 4 pages, 3 figures