Collective excitations of Bose-Einstein Condensate in a Rydberg Atom

TL;DR

This paper explores the behavior of Bose-Einstein condensates within Rydberg atoms, analyzing density profiles and collective excitations, including effects of Rydberg interactions and multi-species systems.

Contribution

It introduces a combined analysis of BECs in Rydberg atoms and extends to multi-species systems, revealing new insights into excitation spectra and interaction effects.

Findings

Rydberg atoms can trap BECs effectively.

Excitation curves shift upward with increased Rydberg interaction.

Roton minima are observed and their depth varies with Rydberg interaction.

Abstract

In this work, we investigated a Bose-Einstein condensate (BEC) inside a Rydberg atom. We first observed the density profile of the system using the Gross-Pitaevskii equation, and then we used the Bogoliubov theory to examine the collective excitation spectra. We have also extended our study by taking into account a hybrid of two BEC species. Again, for this new system, the density profile and the collective excitation are investigated in a similar manner. The results of the BEC for one species reveal that the Rydberg atom can trap the BEC and that the excitation curve moves upward with increasing Rydberg atom interaction. We have seen roton minima for two species of BEC, and the depth of the minima shifts with the Rydberg interaction.