Period-doubling Instability of Bose-Einstein Condensates Induced in Periodically Translated Optical Lattices

TL;DR

This paper reports the observation of period-doubling instability in Bose-Einstein condensates caused by dynamic instability in periodically translated optical lattices, revealing new nonlinear phenomena in quantum gases.

Contribution

It demonstrates the experimental realization of momentum-space period-doubling in BECs due to modulation-induced band coupling, a novel dynamical instability mechanism.

Findings

Observation of momentum distributions indicating period-doubling

Attribution of effect to dynamic instability from band coupling

Evidence of nonlinear dynamical phenomena in quantum gases

Abstract

We observe the formation of momentum distributions indicative of spatial period-doubling of superfluid Bose-Einstein condensates in periodically translated optical lattices. The effect is attributed to dynamic instability of the condensate wavefunction caused by modulation-induced coupling of ground and excited bands.