Bulklike excitations in nanoconfined liquid helium

Article

关键词: SUPERFLUID HE-4;    COLLECTIVE EXCITATIONS;    HIGH-RESOLUTION;    NEUTRON-SCATTERING;    ROTONS;    VISUALIZATION;    DYNAMICS;    ENERGY;    VYCOR;   

DOI  :  10.1103/PhysRevB.95.144509

来源: SCIE

【 摘 要 】

The effects of confinement, disorder, and reduced dimensionality upon quantum fluids have been studied by the adsorption of liquid helium in porous media. The effects of extreme, nanoscale confinement upon its microscopic excitations are not presently understood. Several previous experiments have suggested that at sufficiently low temperature, the roton mean free path is set by the restricted geometry. Here we show that the lifetime of the roton excitation is unaffected when superfluid helium is confined within cylindrical pores only a few nanometers in diameter. The temperature dependence of its lifetime are found to be identical to the bulk fluid, implying that the lifetime is not set by the scale of the confinement. Our results demonstrate that the rotons in the pore center propagate without being modified by the confining media, unlike the collective excitations of classical fluids.

【 授权许可】

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