Role and evidence of order reconstruction in nematic liquid crystal confined systems

Fulvio Bisi, UniversitÓ di Pavia

The notion of surface order force in nematic liquid crystals is presented and contrasted with the notions of similar forces already introduced in the literature. We illustrate how a surface order force could in principle be measured and how it would convey the mechanical signature of an intrinsically nanoscopic phaenomenon, often referred to as order reconstruction, that can be described as bridging two uniaxial state by a wealth of biaxial states, In the last decade, the role of order reconstruction in nematic liquid crystal cells has been assessed in several systems, and a deeper understanding of the analytical aspects of this phenomenon has been reached (Schopol and Sluckin [1], 1987; Palffy-Muhoray et al. [2], 1994; Bisi et al. [3], 2003); also a strong electric field can lead to a biaxial melting (Martinot-Lagarde et al. [4], 2003). The relationships between surface order force and the occurrence of biaxial states of the nematic order tensor is further highlighted.

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