Giant deformations and topological hysteresis of an ordered foam

Abstract

An ordered soap froth is created in a cylindrical tube. By dilating (up to 500%) and compressing the froth, we observe sequences of structural transitions. After dilation followed by compression, the froth recovers its initial structure, but the sequences of intermediate structures upon dilation and upon compression are different. This topological hysteresis is explained by creation and motion of a single dislocation as suggested by a recent work of the present authors.