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Updated: Jul 29, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Second-sound spectroscopy of a nonequilibrium superfluid-normal interface
1BAE Systems, Advanced Information Technologies, 6 New England Executive Place, Burlington, Massachusetts 01803, USA.
Abstract:
An experiment is proposed to test a previously developed theory of the hydrodynamics of a nonequilibrium heat current-induced superfluid-normal interface. It is shown that the interfacial "trapped" second-sound mode predicted by the theory leads to a sharp resonant dip in the reflected signal from an external second-sound pulse propagated toward the interface when its horizontal phase speed matches that of the interface mode. The influence of the interface on thermal fluctuations in the bulk superfluid is shown to lead to slow power dependence of the order parameter, and other quantities, on distance from it.
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