Formation of He Dimer in Nanotube Effect of Adsorption Potential

Abstract

The effect of adsorption potential on the formation of a He dimer in a nanotube is systematically studied. This effect is characterized by two parameters, the effective radius 〈ρ〉 and the effective width Δρ of the one-particle ground-state wave function of a He atom. The binding energy of a ³He dimer exceeds 500 mK at 1.5 Å ≲〈ρ〉≲2.0 Å and Δρ≲0.3 Å at strong adsorption potentials. For larger 〈ρ〉, the binding energy decreases as the adsorption potential increases. We also briefly discuss the magnitude of the binding energy of a ³He dimer in the nanopores where a Fermi-liquid-like state of ³He atoms is recently observed.