Observation of Faraday Waves in a Bose-Einstein Condensate

TL;DR

This paper reports the experimental observation of Faraday waves in a Bose-Einstein condensate, demonstrating how periodic modulation and initial excitations lead to pattern formation and complex nonlinear dynamics.

Contribution

It provides the first experimental evidence of Faraday waves in BECs and explores the nonlinear behaviors under various driving conditions.

Findings

Faraday waves are excited via modulation of transverse confinement.

Spontaneous pattern formation occurs from initial transverse excitations.

Strong driving induces impact-oscillator behavior and multiple mode emergence.

Abstract

Faraday waves in a cigar-shaped Bose-Einstein condensate are created. It is shown that periodically modulating the transverse confinement, and thus the nonlinear interactions in the BEC, excites small amplitude longitudinal oscillations through a parametric resonance. It is also demonstrated that even without the presence of a continuous drive, an initial transverse breathing mode excitation of the condensate leads to spontaneous pattern formation in the longitudinal direction. Finally, the effects of strongly driving the transverse breathing mode with large amplitude are investigated. In this case, impact-oscillator behavior and intriguing nonlinear dynamics, including the gradual emergence of multiple longitudinal modes, are observed.