TEMPERATURE-DEPENDENCE OF THE SPIN POLARIZATION OF A QUANTUM HALL FERROMAGNET

The absolute spin polarization of a two-dimensional electron gas has b een measured as a function of temperature at the nu=1 quantum Hall sta te by magnetoabsorption spectroscopy. We find that the electrons becom e fully polarized as T-->0 and that the loss of spin polarization over the temperature regime of 500 mK to 12 K is consistent with a recentl y proposed continuum quantum ferromagnet model of the spin thermodynam ics of the nu=1 quantum Hall effect state.