R. Berardi, S. Orlandi, C. Zannoni, Columnar phases and field induced biaxiality of a Gay-Berne discotic liquid crystals, PCCP, 2, 2933-2942 (2000)
We have studied a system of discotic particles with central transverse dipole using Monte Carlo (MC) computer simulations at constant
pressure. We have investigated several temperatures corresponding to nematic and columnar liquid crystal phases determining the molecular
and dipolar organizations. Low temperature columnar phases are characterized by local biaxial ordering of dipoles, even if the system
is on the whole uniaxial. However, simulations in the presence of a transverse field for different field and dipole strengths show that
the system has a large susceptivity and easily becomes biaxial, making it potentially interesting for switching applications. An explicit
formulation for the susceptibility in terms of biaxial invariants is derived.