"Dynamics of Electron Bubbles in the Gross-Pitaevskii Model of a Superfluid" Alverto Villois, University of East Anglia

Quantum Systems Unit (Busch U) would like to invite you a seminar by Dr. Alberto Villois, University of East Anglia, UK

Dynamics of Electron Bubbles in the Gross-Pitaevskii Model of a Superfluid
Dr. Alberto VIllois,
Senior Research Associate,
University of East Anglia

Particle impurities represent one of the main existing experimental techniques used to investigate quantised vortices and quantum turbulence in the zero temperature limit of superfluid helium-4.
In this talk, I will discuss the motion of so called electron bubbles in superfluid helium.
The dynamics of the electron bubble is studied in the adiabatic approximation using a minimalist model in which the Gross-Pitaevskii equation is used to describe the superfluid wave-function whereas a Schrödinger equation is used to represent the electron wave-function. This model allows us to recover the key dynamics of the ion-vortex interactions that arise and the subsequent ion-vortex complexes that can form. We determine the vortex-nucleation limited mobility of the free ion to recover values in reasonable agreement with measured data. Moreover, considering the scenario of an ion trapped on the core of a vortex line, we investigate how small and large amplitude Kelvin waves and solitary waves affect the drift velocity of the ion. In particular, we have identified that a Hasimoto soliton-bubble complex propagating along the vortex can arise.

We look forward to seeing many of you at the seminar.

Quantum Systems Unit