Criterion for dominance of directional over size fluctuations in destroying order
For systems that exhibit a second-order phase transition with a spontaneously broken continuous O(N) symmetry at low temperatures, we give a criterion for judging at which temperature T(K) long-range directional fluctuations of the order field destroy the order when approaching the critical temperature from below. The temperature T(K) lies always significantly below the famous Ginzburg temperature T(G) at which size fluctuations of finite range become important.
Kleinert
H
Freie Universitat Berlin, Institut fur Theoretische Physik, Arnimallee 14, D-14195 Berlin, Germany.