Observation of phonon parametric down-conversion in a spherical Bose-Einstein condensate
Abstract
We report the observation of parametric down-conversion of phonons in a spherical Bose-Einstein condensate. The spherical symmetry, which is crucial for observing this phenomenon, is experimentally demonstrated by measuring the collective mode and expansion behavior of the condensate. The low-energy monopole mode is excited by coupling with a high-energy mode with a nearly twice eigen-frequency. The population of the low-energy mode becomes maximum only when the high-energy mode is resonantly excited. Furthermore, we directly observe the parametric down-conversion process in the driving process, through simultaneously probing the two coupling modes. The experimental observation is consistent with the perturbation theory including the gravity effect. This work opens the challenge in related study of the condensate beyond mean-field theory and has potential applications in quantum information.
Cite
@article{arxiv.1805.04727,
title = {Observation of phonon parametric down-conversion in a spherical Bose-Einstein condensate},
author = {Tianyou Gao and Jian-Song Pan and Dongfang Zhang and Lingran Kong and Ruizong Li and Xing Shen and Xiaolong Chen and Shi-Guo Peng and Mingsheng Zhan and W. Vincent Liu and Kaijun Jiang},
journal= {arXiv preprint arXiv:1805.04727},
year = {2018}
}
Comments
10 pages, 4 figures