Application of Braid Groups in 2D Hall System Physics

Book excerpt: In the present treatise progress in topological approach to Hall system physics is reported, including recent achievements in graphene. The new homotopy methods of cyclotron braid subgroups, originally introduced by the authors, turn out to be of particular convenience in order to grasp peculiarity of 2D charged systems upon magnetic field resulting in fractional Hall states. The identified cyclotron braids allow for natural recovery of Laughlin correlations from the first principles, without invoking any artificial constructions as composite fermions with flux tubes or vortices. Progress in understanding of the structure and role of composite fermions in Hall system is provided, which can also lead to some corrections of numerical results in energy minimization made within the traditional formulation of the composite fermion model. The crucial significance of carrier mobility, apart from interaction in creation of the fractional quantum Hall effect (FQHE), is described and supported by recent graphene experiments. Recent advancement in the FQHE field including topological insulators and optical lattices is reviewed and commented upon in terms of the braid group approach. The braid group methods are presented from a more general point of view including proposition of pure braid group application. Book jacket.