Fig. 3: Formation and stability of chiral B* phase in flow of a weakly chiral nematic.

a Gradual transition from \(B\) phase to chiral \({B}^{* }\) phase occurs at lower flow velocity and typically starts from the center of a channel. The small amount of right-handed chiral dopant triggers continuous growth of a single chiral domain with no soliton that is eventually transformed into flow-aligned \(D\) state. Note that with introduction of intrinsic chirality, the distinction between \(B\) and \({B}^{* }\) states becomes blurred. b A static laser beam in a flowing \({B}^{* }\) phase generates a small isotropic region with different rheological properties that allows faster flow, slowing down the flow in the surrounding medium, which thereby transitions into the \(B\) state. c At higher flow velocity, the laser-induced isotropic island cannot split the wrapping \({B}^{* }\) phase as it becomes sufficiently stable over long time and length scales. d Laser-induced nucleation of \(D\) domain in the \(B\) phase. While the domain is growing, it is getting surrounded by greenish-coloured \({B}^{* }\) phase. e A similar experiment at higher flow velocity, where the flow is already in the \({B}^{* }\) state before the quench, creating another \(D\) domain that is stabilised inside the \({B}^{* }\) phase. Scale bars, \(20\ \upmu {\rm{m}}\).