CONTINUUM QUANTUM FERROMAGNETS AT FINITE-TEMPERATURE AND THE QUANTUM HALL-EFFECT

We study finite temperature (T) properties of the continuum quantum fi eld theory of systems with a ferromagnetic ground state. A scaling the ory of the T = 0 system is discussed carefully, and its consequences f or crossovers between different finite T regimes in dimensions 1, 2, a nd 3 are described. The results are compared with recent NMR measureme nts of the magnetization of a quantum Hall system with filling factor v = 1; we predict that the relaxation rate 1/T-1 of this system may ha ve a finite T ''ferromagnetic coherence peak.''