论文标题

铁电列液晶的极地内表面取向:极性单域和扭曲状态电触发

Polar In-Plane Surface Orientation of a Ferroelectric Nematic Liquid Crystal: Polar Monodomains and Twisted State Electro-Optics

论文作者

Chen, Xi, Korblova, Eva, Glaser, Matthew A., Maclennan, Joseph E., Walba, David M., Clark, Noel A.

论文摘要

我们表明,表面相互作用可以在载体上构造铁电流体的三维极化场。铁电列液晶与具有平面极性的表面之间的接触产生了该界面处极化场的首选平面方向。这是形成高极化的流体或玻璃状单构壳的途径,而无需电场极点。例如,在平面表面上的聚酰亚胺膜的单向抛光,从而使四极方向性各向异性也诱导MAC-roscopic在表面上的平面内极顺序,从而实现了包括统一和扭曲状态在内的细胞内部和扭曲状态的各种方位型极性主管结构的形成。在用反平行的,单向抛光在相对表面上获得的π扭矩细胞中,我们演示了三种不同的铁电列源电响应的模式:内在的,固有的,粘度限制的,粘度限制的,场诱导的分子重新定向;域诱导的域壁运动,分隔了相反手性的扭曲状态;以及在场逆转后从细胞板到细胞中心的极化重新定向孤子的传播。抗平行润滑细胞中的刺掺杂的铁电刺激产生螺旋扭曲的宏伟纹理,可以通过野外诱导的极性表面重新定位转变解开。所需的磁场在3 V/mm范围内,表明平面极性锚固能量为WP〜3x10-3 J/m2。

We show that surface interactions can vectorially structure the three-dimensional polariza-tion field of a ferroelectric fluid. The contact between a ferroelectric nematic liquid crystal and a surface with in-plane polarity generates a preferred in-plane orientation of the polarization field at that interface. This is a route to the formation of fluid or glassy monodomains of high polarization without the need for electric field poling. For example, unidirectional buffing of polyimide films on planar surfaces to give quadrupolar in-plane anisotropy also induces mac-roscopic in-plane polar order at the surfaces, enabling the formation of a variety of azimuthal polar director structures in the cell interior, including uniform and twisted states. In a π-twist cell, obtained with antiparallel, unidirectional buffing on opposing surfaces, we demonstrate three distinct modes of ferroelectric nematic electro-optic response: intrinsic, viscosity-limited, field-induced molecular reorientation; field-induced motion of domain walls separating twist-ed states of opposite chirality; and propagation of polarization reorientation solitons from the cell plates to the cell center upon field reversal. Chirally doped ferroelectric nematics in anti-parallel-rubbed cells produce Grandjean textures of helical twist that can be unwound via field-induced polar surface reorientation transitions. Fields required are in the 3 V/mm range, indicating an in-plane polar anchoring energy of wP ~ 3x10-3 J/m2.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源