1. Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
2. National Centre for Computational Design and Discovery of Novel Materials MARVEL, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
3. Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
4. Department of Physics, St. Petersburg State University, St. Petersburg, 199034 Russia.
5. Department of Physics, McCullough Building, Stanford University, Stanford, CA 94305, USA.
6. Stanford Center for Topological Quantum Physics, Stanford University, Stanford, CA 94305, USA.