Quasiparticle properties of an impurity trapped in a superfluid quantized vortex

Atomic polarons are a kind of quasiparticles, namely, impurity atoms dressed by elementary excitations of the surrounding medium via the impurity-medium interactions, which have been actively investigated for cold atomic many-body systems. In the present study we develop the polaron physics by considering a system in which an impurity particle is introduced in a superfluid bosonic medium with a quantum vortex. For a repulsive impurity-medium interaction the impurity particle is bound in the vortex core. This situation is similar to the pinning state that is supposed to be a precursor state proposed for glitch phenomena in neutron stars. In this study, we clarify the polaron picture of an impurity trapped in a quantum vortex. By doing so, we address the polaron's dispersion relation for the momentum along the line of the vortex core, the effective mass, and their dependence on the strength of the impurity-medium interaction.