Twist-bend nematic liquid crystals in high magnetic fields

ORAL

Abstract

We present magneto-optic measurements on two odd-numbered dimer molecules that form the recently discovered twist-bend nematic (N$_{TB}$) phase, which represents a new type of 3-dimensional anisotropic fluid with about 10 nm periodicity and accompanied optical stripes. We show that B $=$ 25T shifts downward the N-N$_{TB}$ phase transitions by almost 1$^{\circ}$C, and explain it quantitatively. We also show that the optical stripes can be unwound by a temperature and material dependent magnetic induction in the range of B $=$ 5-25T. Finally, we propose a Helfrich-Hurault type mechanism for the optical stripe formation. Based on this model we calculate the unwinding magnetic field, and find agreement with our experimental results.

*National Science Foundation (NSF) supported this work under grants DMR 0964765, 1104805, 1121288 and 1307674, as well as the DOE grant DE-FG02-06ER 46331. We thank to C. T. Imrie and Georg Mehl for providing us the material CB7CB.

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Authors

  • Antal Jakli

    • Liquid Crystal Institute, Kent State University
    • Liquid Crystal Institute, Kent State University, Kent. OH 44240
    • Liquid Crystal Institute, Kent State University, Kent, OH 44242

  • Pavan Challa

    • Department of Physics, Kent State University
    • Department of Physics, Kent State University, Kent, OH 44240

  • Volodimyr Borshch

    • Liquid Crystal Institute, Kent State University, Kent. OH 44240

  • Owain Parri

    • Merck Chemicals Ltd., Chilworth Technical Centre, University Parkway, Southampton SO16 7QD, UK

  • Samuel Sprunt

    • Department of Physics, Kent State University
    • Department of Physics, Kent State University, Kent
    • Department of Physics, Kent State University, Kent, OH 44240

  • Oleg D. Lavrentovich

    • Liquid Crystal Institute, Kent State University
    • Liquid Crystal Institute, Kent State University, Kent. OH 44240
    • Liquid Crystal Institute, Kent State University, Kent, OH 44242

  • James T. Gleeson

    • Department of Physics, Kent State University
    • Department of Physics, Kent State University, Kent, OH 44240