Order reconstruction in inverse twisted nematic cell with an applied electric field

• The twice eigenvalue exchange and thrice eigenvalue exchange were observed.
• The twice eigenvalue exchange may have two degenerate configurations.
• The change process of order parameter from positive to negative was shown by tensor Q in two ways.
• The influence of cell gap and applied electric field to eigenvalue exchange was observed.

Order reconstruction in an inverse twisted nematic (ITN) liquid crystal cell with an applied electric field is investigated based on Landau–de Gennes theory and the two-dimensional finite-difference iterative method. Twice eigenvalue exchange in three-axis layer configuration, thrice eigenvalue exchange in four-axis layer configuration, and negative order parameter uniaxial twisted state exist in this cell, which can be described by the order parameter tensor Q in equilibrium state. The twice eigenvalue exchange also has two degenerate configurations with reduced electric field E from 0.8 to 2.8 in 10ξ cell (ξ   is the biaxial correlation length). Moreover, two critical cell gaps dc⁎⁎=7ξ and dc⁎=12ξ are included in the study of the ITN cell. When d≤dc⁎⁎, only the eigenvalue change state exists. When d≥dc⁎, only a positive order parameter uniaxial twisted state exists near the threshold electric field. When dc⁎⁎