Control of transient biaxial order in calamitic nematics

The biaxial order reconstruction in nematics (BORN) is a dynamical effect which can change the topology of nematic textures. The BORN can be induced in a nematic material submitted to strong external constraints, as in the case of bulk textural distortions due to an electric field in a pi cell. In this work, we show how suitable dopants for a thermotropic calamitic nematic can influence its transient biaxial order and, hence, the electric BORN threshold. (c) 2007 American Institute of Physics.