Chiral nematic liquid crystals exhibit both a helical planar ground state with uniform twist and a metastable defect-rich focal conic texture, and can be switched between the two microstructures via application of transient voltage pulses. In this work, we model these electrically-induced texture transitions using finite difference methods to examine resulting microstructural evolution, the first time this transition has been modeled in three dimensions. We analyze the planar to focal conic, focal conic to planar, and planar to planar transitions depending on voltage pulse magnitude. We consider first the special case of chiral nematics with matched twist and bend elastic constants. Results show a variety of defect-rich morphologies in the disordered focal conic texture and demonstrate a fast recovery of the planar ground state on switching without formation of a transient planar state. We evaluate both texture microstructural evolution as well as cell capacitance. Beyond the single elastic constant approximation, we evaluate the planar to transient-planar as well as the planar to Helfrich-deformed transitions in simulations of a liquid crystal compound with different elastic constants. Our methods represent the evolving microstructure as a uniaxial director field, with relaxation dynamics calculated from a tensor representation so that half charge disclination defects are not suppressed. We discuss potential application of these computationally efficient three-dimensional modeling approaches for design and optimization of chiral nematic devices.
Electro-optic switching of dielectrically negative nematic through nanosecond electric modification of order parameter (NEMOP)
我们目前的实验研究纳秒电修改的序参量（NEMOP）在各种负介电各向异性的介电材料。该研究表明，NEMOP能够实现大幅度的快速（纳秒）电光响应，场致双折射的数量级为0.01，品质因数（FoM）的数量级为$10^4$ $μ$ m $^2/$ s;后者的数量级高于传统上用于电光MEMS器件的弗雷德里克效应的FoM。NEMOP响应的幅度通常在具有较大介电各向异性和较高自然（无场）双折射的向列相中更强。
Surface Alignment, Anchoring Transitions, Optical Properties, and Topological Defects in the Thermotropic Nematic Phase of an Organo-Siloxane Tetrapodes
Laser-Induced Topological Toggle Switching at Room Temperature in the van der Waals Ferromagnet Fe3GaTe2
University College London（伦敦大学学院）；Korea Advanced Institute of Science and Technology (KAIST)（韩国科学技术院）；University of Exeter（埃克塞特大学）；The University of Edinburgh（爱丁堡大学）
Decoupled domain-texture switching from magnetic easy axis in kagome ferromagnet EuTi3Bi4
Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Renmin University of China（中国人民大学）；Fudan University（复旦大学）
Curvature-guided topology and self-assembly in chiral nematics and liquid-crystal colloids
University of Colorado Boulder（科罗拉多大学博尔德分校）；University of Colorado, Boulder（科罗拉多大学博尔德分校）；National Renewable Energy Laboratory（国家可再生能源实验室）；Hiroshima University（广岛大学）；Universidade de Lisboa（里斯本大学）
Hybrid Topological Defects in Ferroelectric Nematic Fluids
Southern University of Science and Technology（南方科技大学）；The Hong Kong University of Science and Technology（香港科技大学）；South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology（华南理工大学 emergent soft matter 学院/华南软物质科学与技术先进研究院）；Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology（华南理工大学 广东省功能性与智能性杂化材料器件重点实验室）；Center for Complex Flows and Soft Matter Research, Southern University of Science and Technology（南方科技大学 复杂流动与软物质研究中心）
Tunable chiral and nematic states in the triple-Q antiferromagnet Co$_{1/3}$TaS$_2$
National High Magnetic Field Laboratory, Los Alamos National Lab（国家高磁场实验室，洛斯阿拉莫斯国家实验室）；Materials Science and Technology Division, Oak Ridge National Laboratory（橡树岭国家实验室材料科学与技术部）；Department of Physics and Astronomy, Seoul National University（首尔大学物理与天文学系）；Department of Physics and Astronomy, University of Tennessee, Knoxville（田纳西大学诺克斯维尔分校物理与天文学系）；Shull Wollan Center—A Joint Institute for Neutron Sciences, Oak Ridge National Laboratory（橡树岭国家实验室舒尔-沃兰中子科学联合研究所）；Institute of Applied Physics, Seoul National University（首尔大学应用物理研究所）
Ferroelectric switching of odd-parity magnon spin splitting
Tsinghua University（清华大学）；Cornell University（康奈尔大学）；Ningbo Institute of Digital Twin, Eastern Institute of Technology（宁波数字孪生研究院，东方理工学院）；Department of Physics, Tsinghua University（清华大学物理系）；Department of Physics, University of Science and Technology of China（中国科学技术大学物理系）；University at Buffalo, State University of New York（纽约州立大学布法罗分校）；Kavli Institute at Cornell for Nanoscale Science（康奈尔纳米科学卡弗里研究所）
