Soliton walls paired by polar surface interactions in a ferroelectric nematic liquid crystal

Bijaya Basnet; Mojtaba Rajabi; Hao Wang; Priyanka Kumari; Kamal Thapa; Sanjoy Paul; Maxim O Lavrentovich; Oleg D Lavrentovich

doi:10.1038/s41467-022-31593-w

Soliton walls paired by polar surface interactions in a ferroelectric nematic liquid crystal

Nat Commun. 2022 Jul 7;13(1):3932. doi: 10.1038/s41467-022-31593-w.

Authors

Bijaya Basnet^#^{1

2}, Mojtaba Rajabi^#^{1

3}, Hao Wang^#¹, Priyanka Kumari^{1

2}, Kamal Thapa^{1

3}, Sanjoy Paul¹, Maxim O Lavrentovich⁴, Oleg D Lavrentovich^{5

6

7}

Affiliations

¹ Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.
² Materials Science Graduate Program, Kent State University, Kent, OH, 44242, USA.
³ Department of Physics, Kent State University, Kent, OH, 44242, USA.
⁴ Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.
⁵ Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA. olavrent@kent.edu.
⁶ Materials Science Graduate Program, Kent State University, Kent, OH, 44242, USA. olavrent@kent.edu.
⁷ Department of Physics, Kent State University, Kent, OH, 44242, USA. olavrent@kent.edu.

^# Contributed equally.

Abstract

Surface interactions are responsible for many properties of condensed matter, ranging from crystal faceting to the kinetics of phase transitions. Usually, these interactions are polar along the normal to the interface and apolar within the interface. Here we demonstrate that polar in-plane surface interactions of a ferroelectric nematic N_F produce polar monodomains in micron-thin planar cells and stripes of an alternating electric polarization, separated by [Formula: see text] domain walls, in thicker slabs. The surface polarity binds together pairs of these walls, yielding a total polarization rotation by [Formula: see text]. The polar contribution to the total surface anchoring strength is on the order of 10%. The domain walls involve splay, bend, and twist of the polarization. The structure suggests that the splay elastic constant is larger than the bend modulus. The [Formula: see text] pairs resemble domain walls in cosmology models with biased vacuums and ferromagnets in an external magnetic field.