Quantum Tunneling inHe3Monolayers

Abstract

Measurements are reported of NMR linewidth, $\frac{1}{T_2}$, for ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ atoms adsorbed on Grafoil at 1 K for various quantities of gas adsorbed. The data show three well-defined regions corresponding to a two-dimensional fluid, a two-dimensional solid, and a region where a second layer of adsorbed atoms is forming. A sharp minimum in $T_2$ gives a precise indication of monolayer completion. A theory for tunneling in the two-dimensional solid is presented.