Search for spin liquid state in sub-monolayer 3He adsorbed on HD-preplated graphite

NMR studies of sub-monolayer solid 3He adsorbed on a bilayer of HD-preplated graphite have been made down to 100 (mu)K, which is more than one order of magnitude smaller than the exchange energy (J). In the highly frustrated anti-ferromagnetic region, the magnetization obeys a Curie–Weiss law even at temperatures around J and then increases gradually down to 100 (mu)K. Nevertheless, it does not show any anomalous behavior corresponding to the existence of the spin gap. The normalized magnetization versus the reduced temperature (T/J) is independent of the density just after solidification. This fact is consistent with the result in the high-temperature region where the main multiple spin exchanges have a similar density dependence in the present density region.