Self-Consistent Model of Roton Cluster Excitations in Liquid Helium II

V. I. Kruglov; M. J. Collett

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arXiv · cond-mat/0605442

Self-Consistent Model of Roton Cluster Excitations in Liquid Helium II

V. I. Kruglov·M. J. Collett

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Abstract

We have proposed a model of roton cluster excitations in liquid helium~II based on a Schrödinger-type equation with a self-consistent confining potential. We have derived an equation for the number of atoms in roton excitations, which can be treated as quantum $3{\rm D}$ solitons, depending on vibrational quantum numbers. It is shown that the smallest roton cluster is in the symmetric vibrational quantum state and consists of 13 helium atoms. We have also used a modified Born approximation to calculate the $s$-scattering length for helium atoms. This allows us to calculate all parameters of Landau's roton excitation spectrum, in agreement to high accuracy with experimental measurements from neutron scattering.

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V. I. Kruglov, M. J. Collett. 2006-05-18. Self-Consistent Model of Roton Cluster Excitations in Liquid Helium II. https://arxiv.org/abs/cond-mat/0605442

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