Diagrammatic damage spreading in the quantum Heisenberg ferromagnet

The Handscomb Monte Carlo method is a powerful tool for the investigation o f the critical properties of quantum spin models. The sample space in this technique is constructed over the space of ordered Mayer's diagrams and it is the diagrammatic series of the partition function that is calculated by means of the Monte Carlo method. In this work, we apply a damage-spreading algorithm to study the quantum S = 1/2 Heisenberg 3D ferromagnet. The damag e is introduced as a perturbation in the bond structure of the Mayer's diag rams. A cyclic Hamming distance is shown to be closely related to the stati c spin susceptibility. Using a phenomenological renormalization group analy sis we show that the cyclic Hamming distance scales near T-c as NDc = L-gam ma/nu g(tL(1/nu)), with nu = 0.7 and gamma/nu = 1.99. (C) 2000 Elsevier Sci ence B.V. All rights reserved.