Topological transformations of Hopf solitons in chiral ferromagnets and liquid crystals

被引:49
作者
Tai, Jung-Shen B. [1 ,2 ]
Ackerman, Paul J. [1 ,2 ]
Smalyukh, Ivan I. [1 ,2 ,3 ,4 ,5 ,6 ]
机构
[1] Univ Colorado, Dept Phys, Boulder, CO 80309 USA
[2] Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA
[3] Univ Colorado, Mat Sci & Engn Program, Boulder, CO 80309 USA
[4] Univ Colorado, Soft Mat Res Ctr, Boulder, CO 80309 USA
[5] Natl Renewable Energy Lab, Renewable & Sustainable Energy Inst, Boulder, CO 80309 USA
[6] Univ Colorado, Boulder, CO 80309 USA
基金
美国国家科学基金会;
关键词
three-dimensional soliton; self-assembly; ferromagnetism; chirality; KNOTS;
D O I
10.1073/pnas.1716887115
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Liquid crystals are widely known for their facile responses to external fields, which forms a basis of the modern information display technology. However, switching of molecular alignment field configurations typically involves topologically trivial structures, although singular line and point defects often appear as short-lived transient states. Here, we demonstrate electric and magnetic switching of nonsingular solitonic structures in chiral nematic and ferromagnetic liquid crystals. These topological soliton structures are characterized by Hopf indices, integers corresponding to the numbers of times that closed-loop-like spatial regions (dubbed "preimages") of two different single orientations of rod-like molecules or magnetization are linked with each other. We show that both dielectric and ferromagnetic response of the studied material systems allow for stabilizing a host of topological solitons with different Hopf indices. The field transformations during such switching are continuous when Hopf indices remain unchanged, even when involving transformations of preimages, but discontinuous otherwise.
引用
收藏
页码:921 / 926
页数:6
相关论文
共 26 条
  • [1] Diversity of Knot Solitons in Liquid Crystals Manifested by Linking of Preimages in Torons and Hopfions
    Ackerman, Paul J.
    Smalyukh, Ivan I.
    [J]. PHYSICAL REVIEW X, 2017, 7 (01):
  • [2] Ackerman PJ, 2017, NAT MATER, V16, P426, DOI [10.1038/NMAT4826, 10.1038/nmat4826]
  • [3] Hopfions interaction from the viewpoint of the product ansatz
    Acus, A.
    Norvaisas, E.
    Shnir, Ya.
    [J]. PHYSICS LETTERS B, 2014, 733 : 15 - 20
  • [4] Knots as stable soliton solutions in a three-dimensional classical field theory
    Battye, RA
    Sutcliffe, PM
    [J]. PHYSICAL REVIEW LETTERS, 1998, 81 (22) : 4798 - 4801
  • [5] Hopf Skyrmion in QCD with adjoint quarks
    Bolognesi, S.
    Shifman, M.
    [J]. PHYSICAL REVIEW D, 2007, 75 (06):
  • [6] Bott R., 1982, Differential forms in algebraic topology, V82
  • [7] Chaikin P. M., 2000, Principles of Condensed Matter Physics
  • [8] Liquid Crystal Display-Present Status and Emerging Technology
    Cheng, Ko-Ting
    [J]. CURRENT TRENDS OF OPTICS AND PHOTONICS, 2015, 129 : 289 - 307
  • [9] de Gennes P G., 1995, The Physics of Liquid Crystals, DOI DOI 10.1063/1.2808028
  • [10] Stable knot-like structures in classical field theory
    Faddeev, L
    Niemi, AJ
    [J]. NATURE, 1997, 387 (6628) : 58 - 61