Twist-Bend Nematic Phase: Role of Third-Order Legendre Polynomial Term in Chiral Interaction Potential

Abstract

Using a mean-field theory, a twist-bend nematic (NTB) phase has been described. In addition to second-order Legendre polynomial term, the chiral interaction potential includes third-order Legendre polynomial term also. It considers the coupling between a nematic director and a pitch axis of the NTB phase. The distortion free energy, order parameter for twist-bend nematic, and orientational distribution function in equilibrium state have been calculated. Based on the free energy minimization, we obtain that the inclusion of third-order Legendre polynomial term in interaction energy makes NTB phase more stable. © 2020, Sociedade Brasileira de Física.