Exchange and Spectral Density in Two-Dimensional Helium-3: AT1Study

Abstract

$T_1$ measurements have been performed on the solid phase of helium-3 adsorbed on Grafoil. A theory has been developed to interpret these data on the basis of the hypothesis of a single correlation time for the exchange-induced spin motion. We infer that the relaxation is mediated by the internuclear dipolar interaction. We show how the $T_1$-minima data together with exact moment and hydrodynamic calculations may be used to approximate the spectral functions over their whole range. Thus we obtain numerical values for the exchange frequency for all regions of data. Our method is quite general and applicable to other systems.