Inelastic scattering of xenon atoms by quantized vortices in superfluids

TL;DR

This paper investigates how xenon atoms interact with quantized vortices in superfluid helium, revealing that inelastic scattering involves Kelvin wave generation and providing a capture criterion based on binding energy.

Contribution

It introduces a semi-classical matter wave model to simulate impurity-vortex interactions, extending understanding of inelastic scattering and vortex dynamics in superfluids.

Findings

Inelastic scattering involves Kelvin wave excitation.

Capture of impurities depends on binding energy.

Simulation results align with experimental observations.

Abstract

We study inelastic interactions of particles with quantized vortices in superfluids by using a semi-classical matter wave theory that is analogous to the Landau two-fluid equations, but allows for the vortex dynamics. The research is motivated by recent experiments on xenon doped helium nanodroplets that show clustering of the impurities along the vortex cores. We numerically simulate the dynamics of trapping and interactions of xenon atoms by quantized vortices in superfluid helium and the obtained results can be extended to scattering of other impurities by quantized vortices. Different energies and impact parameters of incident particles are considered. We show that inelastic scattering is closely linked to the generation of Kelvin waves along a quantized vortex during the interaction even if there is no capture. The capture criterion of an impurity is formulated in terms of the binding energy.