Shedding light onto topological insulator beads: perspectives for   optical tweezing application
  The interaction of electromagnetic radiation with a spheric-type three-dimensional topological insulator (TI) bead is described within classical optics framework. By virtue of the topological magnetoelectric effect (TMEE) experienced by reflected and transmitted rays at the TI surface, there appears a net constant force on the spherical bead which is proportional to the fine structure constant times the incident radiation power. Such an uniform dynamics (constant acceleration) may be particularly useful for optical tweeezing techniques, for instance, to investigate a DNA strip or a membrane piece under stretching as well as to displace a tiny object by means of purely optical control. 
Yuri G. Muller, Winder A. Moura-Melo, Jakson M. Fonseca
cond-mat.mes-hall physics.optics