Dynamics of topological defects in multi-component and spinor Bose-Einstein Condensates (BORGHM_U26EMP)

Modern experimental techniques have brought atomic quantum gases to the forefront as systems where objects and processes may be studied that find analogues from condensed-matter physics to early-universe cosmology [1]. These are topological defects and textures, such as superfluid vortices, whose fundamental properties arise generically from topology. Recent experiments have created vortices representing exotic symmetries arising from the spin of the constituent atoms [2].

Topological excitations are also fundamental in important dynamical process, including quantum phase transitions [3]. Superfluid atomic quantum gases with spin degrees of freedom provide versatile testbeds for topological defects. In this PhD project, we will use numerical simulations to theoretically study the dynamics of topological excitations in multi-component and spinor Bose-Einstein condensates (BECs), with relevance to phase transitions, turbulence and topological interfaces.

The aim of the project is to understand the role of spin and multi-component interactions in the motion and collision of vortices, which become particularly intriguing in systems with complex, underlying broken symmetries. Previous results indicate that surprising new energetic scaling regimes arise already in a two-component BEC [4]. In this project we ask how this picture is modified when the atomic spin is allowed full dynamical freedom.

We will use mean-field methods to model the spinor condensate, which requires numericall