报告题目：Spontaneous pattern formation in a driven Bose-Einstein Condensate

报告人：Prof. Cheng Chin  (James Franck Institute, Enrico Fermi Institute and Department of Physics,University of Chicago)

时间：2019年9月9日（周一）下午5:00

地点：光电所二层报告厅

摘要：Pattern formation is ubiquitous in nature, from morphogenesis, cloud formation to galaxy filamentation.  More often than not, patterns arise in a medium far from equilibrium due to the interplay between dynamical instability and nonlinear wave mixing. We report, based on momentum and real space pattern recognition, spontaneous formation of density patterns with D2, D4and D6 symmetries in Bose-Einstein condensates with atomic interactions driven at two frequencies.  The symmetry of the pattern is controlled by the ratio of the frequencies.  The D6 density waves, in particular, arise from a resonant wave mixing process that coherently correlates and enhances all 6 excitations that support the symmetry.