Spontaneous Formation of Surface Patterns in a Driven Bose-Einstein Condensate

10 September 2021

Photo: AG Schmelcher

Experimental observation of star-shaped condensates.

In a collaboration of theory and experiment this work explored processes of pattern formation in radiofrequency driven Bose-Einstein condensates. Two-dimensional star-shaped patterns with l-fold symmetry, ranging from quadrupole (l=2) to heptagon modes (l=7), have been parametrically excited by modulating the atomic interactions via so-called Feshbach resonances. Mathematical techniques based on an effective Mathieu equation and Floquet analysis are utilized here to unravel the instability conditions and study the surface modes in a trapped superfluid. The resonant frequencies of the patterns helped us to understand the dispersion relation of the collective excitations. The experimental results are in excellent agreement with the theoretical mean-field framework. This work opens a new pathway for generating higher-lying collective excitations with applications, such as the probing of exotic properties of quantum fluids and providing a generation mechanism of quantum turbulence.

Publication

K. Kwon, S. Huh, K. Kim, K. Mukherjee, S.I. Mistakidis, D.K. Maity, P.G. Kevrekidis, S. Majumder, P. Schmelcher and J.-Y. Choi

Spontaneous Formation of Star-Shaped Surface Patterns in a Driven Bose-Einstein Condensate

Physical Review Letters 127, 113001 (2021)