Oscillation and Instability of a Soliton in Superfluid Atomic Gas

Mark A. Hoefer, JiaJia Chang, Chris Hamner +1 more

We investigate the dynamics of two miscible superfluids experiencing fast counterflow in a narrow channel. The superfluids are formed by two distinguishable components of a trapped dilute-gas Bose-Einstein condensate (BEC). The onset of counterflow-induced modulational instability throughout the cloud is observed and shown to lead to the proliferation of dark-dark vector solitons. These solitons do not exist in single-component systems, exhibit intriguing beating dynamics, and can experience a transverse instability leading to vortex line structures. Experimental results and multidimensional numerical simulations are presented.

R. Murali

Yusuke Ozaki, Kazuma Nagao, Ippei Danshita +1 more

This work analyzes effects of weak quantum fluctuations on the dynamical stability of two types of dark solitons in a one-dimensional Bose gas in an optical lattice. It reveals the classical-to-quantum crossover behavior of the soliton stability, which can be used for experimentally diagnose whether the instability of a dark soliton is due to quantum fluctuations or classical dynamical instability.

Kazuya Fujimoto, Makoto Tsubota

P. E. S. Tavares, Gustavo Deczka Telles, R. F. Shiozaki +2 more

Hikaru Tamura, Sergei Khlebnikov, Cheng-An Chen +1 more

The authors create a spatially bounded supersonic region in a two-dimensional atomic superfluid, forming an acoustic analogue of a black-hole horizon. The observed superflow appears to be modulated by quasi-periodic bursts of superluminal signals. By measuring their frequencies, the authors find agreement with numerical simulations of soliton oscillation frequencies within the black-hole horizon, where solitons are emitted due to the Landau instability.