Flexoelectric switching in cholesteric blue phases
Flexoelectric switching in cholesteric blue phases
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胆甾蓝相中的挠曲电开关
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
E. Orlandini
中科院分区：
文献类型：
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作者：
A. Tiribocchi;M. Cates;G. Gonnella;D. Marenduzzo;E. Orlandini
我们提出了挠曲电蓝相网络（无论是在本体还是在限制下）对应用场的响应的计算机模拟。我们发现蓝相 I 向错网络和沿施加场方向的平行向错阵列之间存在整体转变。关闭磁场后，系统无法重建原始蓝相，而是陷入亚稳态。相对而言，蓝相II受场的影响要小得多。在受限样品中，壁上的锚定和装置的几何形状导致进一步结构的稳定，包括场对准向错环、张开向列图案和更多亚稳态。我们的结果与理解一类由双介晶液晶组成的新型“超稳定”蓝相的开关动力学相关，因为这些材料结合了异常大的挠电系数和低或接近零的介电各向异性。
We present computer simulations of the response of a flexoelectric blue phase network, either in bulk or under confinement, to an applied field. We find a transition in the bulk between the blue phase I disclination network and a parallel array of disclinations along the direction of the applied field. Upon switching off the field, the system is unable to reconstruct the original blue phase but gets stuck in a metastable phase. Blue phase II is comparatively much less affected by the field. In confined samples, the anchoring at the walls and the geometry of the device lead to the stabilisation of further structures, including field-aligned disclination loops, splayed nematic patterns, and yet more metastable states. Our results are relevant to the understanding of the switching dynamics for a class of new, “superstable”, blue phases which are composed of bimesogenic liquid crystals, as these materials combine anomalously large flexoelectric coefficients, and low or near-zero dielectric anisotropy.