Theoretische Physik III, Universit?t Augsburg, 86135 Augsburg, Germany, DE Sektion Physik, Ludwig-Maximilians-Universit?t München, Theresienstrasse 37, 80333 München, Germany, DE
Abstract:
We present a field-theoretic renormalization group calculation in two loop order for classical O(N)-models with an inverse square interaction in the vicinity of their lower critical dimensionality one. The magnetic susceptibility
at low temperatures is shown to diverge like with a=(N-2)/(N-1) and . From a comparison with the exactly solvable Haldane-Shastry model we find that the same temperature dependence applies also
to ferromagnetic quantum spin chains.
Received: 20 February 1998 / Revised: 27 April 1998 / Accepted: 30 April 1998