ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarSalamon PéterWigner RCP SZFILiquid crystal spherical caps in 
magnetic fieldTuesday, 12 January 2021, 10:00, video conference, 
https://letsmeet.wigner.hu/szeminariumWe investigated the static and dynamic 
behavior of plano-convex lens shaped droplets of a liquid crystal in the 
presence of magnetic field by experiments and theoretical calculations [1]. 
The structure of the average molecular orientation field (the director) was 
investigated as a function of magnetic field. Polarizing optical microscopy 
indicated that a disclination line appears inside the droplet, whose 
localization depends strongly on the tilt angle of magnetic field with 
respect to the flat base plane. We found dynamical behavior of the defect 
wall, and studied how the motion of disclination depends on experimental 
conditions such as the magnitude or direction of the applied magnetic field. 
The system under scope can be used as a liquid optical lens with light 
polarization dependent focal length, tunable by magnetic field. Our work 
reveals the nature of external field induced defect formation that may act 
adversely in applications, and we show in what conditions the disclination 
formation can be eliminated.Reference[1] P. Salamon, Z. Karaszi, V. 
Kenderesi, Á. Buka, A. Jákli, Liquid crystal spherical caps in magnetic 
fields, Phys. Rev. Research 2, 023261 (2020) Minden érdeklődőt szívesen 
látunk! - Everyone is welcome to attend.Róbert Juhászsem-admin AT szfki.hu