Rydberg excitation of a Bose-Einstein condensate

TL;DR

This study demonstrates controlled Rydberg excitation of Bose-Einstein condensates in various trapping geometries, revealing collective behaviors and interactions influenced by external electric fields and optical lattices.

Contribution

It introduces a method for precise Rydberg excitation in BECs with controlled electric fields and explores collective excitation phenomena in different trap configurations.

Findings

Successful two-photon Rydberg excitation in BECs.

Observation of collective Rydberg excitations in optical lattices.

Agreement of experimental results with dipole-dipole interaction models.

Abstract

We have performed two-photon excitation via the 6P3/2 state to n=50-80 S or D Rydberg state in Bose-Einstein condensates of rubidium atoms. The Rydberg excitation was performed in a quartz cell, where electric fields generated by plates external to the cell created electric charges on the cell walls. Avoiding accumulation of the charges and realizing good control over the applied electric field was obtained when the fields were applied only for a short time, typically a few microseconds. Rydberg excitations of the Bose-Einstein condensates loaded into quasi one-dimensional traps and in optical lattices have been investigated. The results for condensates expanded to different sizes in the one-dimensional trap agree well with the intuitive picture of a chain of Rydberg excitations controlled by the dipole-dipole interaction. The optical lattice applied along the one-dimensional geometry produces localized, collective Rydberg excitations controlled by the nearest-neighbour blockade.