ABSTRACT
We have performed thermodynamic and NMR relaxation time measurements of 3He adsorbed in the pores of the mesoporous molecular sieve MCM-41 at temperatures down to 1.7 K and at a range of frequencies up to 240 kHz. The MCM-41 substrate comprises a uniform array of quasi-1D straight pores with a diameter of 2.3 nm. We preplated the pores with a monolayer of 4He to achieve an effective diameter of 1.6 nm at low temperatures. We made NMR measurements as a function of line density and frequency to investigate the spin dynamics and the effect of dimensionality. We observed T(1) is proportional to ω1/2, which is characteristic of one-dimensional diffusion. At these temperatures this arises from a classical size effect in the narrow pores. Our results demonstrate the possibility to study the spin dynamics of a 1D Tomonaga-Luttinger liquid at lower temperatures, where the 3He liquid will constitute a quantum 1D system.
ABSTRACT
The heat capacity and magnetization of a fluid 3He monolayer adsorbed on graphite plated with a bilayer of HD have been measured in the temperature range 1-60 mK. Approaching the density at which the monolayer solidifies into a sqrt[7]xsqrt[7] commensurate solid, we observe an apparent divergence of the effective mass and magnetization corresponding to a T=0 Mott-Hubbard transition between a 2D Fermi liquid and a magnetically disordered solid. The observations are consistent with the Brinkman-Rice-Anderson-Vollhardt scenario for a metal-insulator transition. We observe a leading order T2 correction to the linear term in heat capacity.
