Disorder-averaged Binder ratio in site-diluted Heisenberg models

It is demonstrated via a numerical experiment (a Monte Carlo simulation) in the context of three-dimensional site-diluted Heisenberg spin systems that a functional dependence of the Binder ratio ($V_4$) on the order parameter correlation length ($\xi / L$) requires a modification to the usual definition of $V_4$ in disordered systems. An appropriate disorder averaging procedure is proposed.