Possible one-dimensional He-3 quantum fluid formed in nanopores

Heat capacity measurements have been made down to 5 mK for He-3 fluid films adsorbed in one-dimensional (1D) nanometer-scale pores, 28 Angstrom in diameter, preplated with He-4 of 1.47 atomic layers. At low He-3 density, the heat capacity shows a density-dependent, Schottky-like peak near 150 mK asymptoting to the value corresponding to a 2D Boltzmann gas at high temperatures. The peak behavior is attributed to the crossover from a 2D gas to a 1D state at low temperatures. The degenerate state of the 1D He-3 fluid is indicated by a predominantly linear temperature dependence below about 30 mK.