Leander Fiedler Leibniz Universität Hannover Papers Jones index, secret sharing and total quantum dimension Leander Fiedler, Pieter Naaijkens, Tobias J. Osborne August 08, 2016 open access link New J. Phys. 19 023039 (2017) Haag duality for Kitaev's quantum double model for abelian groups Leander Fiedler, Pieter Naaijkens June 04, 2014 open access link Rev. Math. Phys. 27, 1550021 (2015)