Landau-de Gennes modeling of confinement effects and cybotactic clusters in bent-core nematic liquid crystals

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Han, Yucen and Rajamanickam, Prabakaran and Alturki, Bedour and Majumdar, Apala (2026) Landau-de Gennes modeling of confinement effects and cybotactic clusters in bent-core nematic liquid crystals. Physical Review E, 113 (2). 025403. ISSN 2470-0053 (https://doi.org/10.1103/w85s-mwn3)

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Abstract

We study bent-core nematic (BCN) systems in two-dimensional (2D) and three-dimensional (3D) settings, focusing on the role of cybotactic clusters, phase transitions, confinement effects, and applied external fields. We propose a generalized version of Madhusudana's two-state model for BCNs [] with two order parameters: Q g to describe the ambient ground-state (GS) molecules and Q c to describe the additional ordering induced by the cybotactic clusters. The equilibria are modeled by minimizers of an appropriately defined free energy, with an empirical coupling term between Q g and Q c . We demonstrate two phase transitions in spatially homogeneous 3D BCN systems at fixed temperatures: a first-order nematic-paranematic transition followed by a paranematic-isotropic phase transition driven by the GS-cluster coupling. We also numerically compute and give heuristic insights into solution landscapes of confined BCN systems on 2D square domains, tailored by the GS-cluster coupling, temperature, and external fields. This benchmark example illustrates the potential of this generalized model to capture tunable director profiles, cluster properties, and potential biaxiality induced by antagonistic Q g and Q c profiles.

ORCID iDs

Han, Yucen, Rajamanickam, Prabakaran ORCID logoORCID: https://orcid.org/0000-0003-1240-0362, Alturki, Bedour and Majumdar, Apala ORCID logoORCID: https://orcid.org/0000-0003-4802-6720;
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