Strongly correlated two dimensional fluid 3He

A two dimensional system of strongly correlated fermions can be realised by a fluid monolayer of He-3 adsorbed on an atomically flat surface. We report extensive measurements of the heat capacity, c, of He-3 adsorbed an graphite plated with two layers of hydrogen deuteride (HD) over a closely spaced grid of coverages in the temperature range 1-80mK. The quasiparticle effective mass ratio, inferred from the linear temperature coefficient of the heat capacity, increases from near unity at low densities and appears to diverge approaching localisation. The maximum value of m*/m toe are able to unambiguously extract from the data is 13 at a density 5 nm(-2). At this density c/T is temperature independent only below 5mK. The behaviour of m*/m and F-0(a), inferred from magnetization data, are consistent with the model of almost-localised fermions. We can trade the evolution of strong finite temperature deviations from Fermi liquid behaviour as the density of the film and hence m*/m are increased. At sufficiently low temperature this correction is of T-2 form going over to a large TlnT deviation for T > 0.05 T-F*, as predicted for 2D spin fluctuations. Thus in this system 'non-Fermi liquid' behaviour extends to very low temperatures in the strongly correlated, large m*/m, limit.