Heat capacity of helium in cylindrical environments

2019-12-29 05:56:35

He fluid We phonon adsorbed

责任者: Gatica, S.M.;Hernandez, E.S.;Szybisz, L. 单位: Dept. de Fisica, Univ. de Buenos Aires, Argentina 来源出处: Physical Review B (Condensed Matter and Materials Physics)(Phys. Rev., B, Condens, Matter Mater. Phys. (USA)),2003/10/01,68(14):144501-1 摘要: We perform a systematic investigation of the structure, elementary, and phonon excitations of quantum fluid 4He adsorbed in the interior of carbon nanotubes. We show that the helium fluid inside the cylinder behaves exactly as in planar films on a graphite substrate, presenting the same kind of layering transition. This tendency is confirmed by the behavior of a single 3He impurity diluted into adsorbed 4He. We also present a simple description of the lowest excitation modes of the adsorbed fluid and compute the low-temperature contribution of the phonon spectrum to the specific heat, which displays the dimensionality characteristics reported in previous works 关键词: carbon nanotubes;phonons;specific heat;superfluid helium-4;wave functions;cylindrical environments;phonon excitations;quantum fluid 4He;carbon nanotubes;layering transition;lowest excitation modes;adsorbed fluid;low-temperature contribution;heat capacity;phonon spectrum;C-He