Fig. 3: Spontaneous reversal of rotation direction.
From: Formation of stable and responsive collective states in suspensions of active colloids
a Time-dependent rotational and orientational order parameters OR and OP during a spontaneous change of the swirl’s sense of rotation. b Histogram of the correlation between OR and OP obtained from measurements, including about 50 rotation reversals. c–h Spatially resolved rotational order parameter at different times (marked in a). Scale bar is 30 μm. All measurements were performed for α = 360°, Rp = ∞, Δ = 67.5°.
