Second-Layer Solidification of ³ He on Graphite: a Numerical Study

Abstract

A recent experimental study by Greywall and Busch of <sup>3</sup>He bilayers adsorbed on graphite strongly indicates that the second layer solidifies at a relatively low density. This is consistent with an earlier heat capacity experiment but disagrees with recent neutron scattering measurements. Using path integral and variational wavefunction techniques, we find that a recently proposed √7 × √7 registered structure is stable at low temperature and melts at approximately 1 K in agreement with the early heat capacity measurements.