Janik Kailasvuori (MPIPKS (Dresden))
Semiclassical spin-coherent kinetic equations can be derived from quantum theory with many different formalisms. For 2d Dirac electrons (e.g. in graphene, 3d topological insulators, ...) we found to our surprise that well established formalisms give different results. We have been able to point out the exact source of the discrepancy and raise fundamental questions about how to derive semiclassical kinetic equation when some quantum coherence must be retained. Further, in monolayer graphene we make the unintuitive finding that there could be finite electron-hole coherent quantum effects even far away from the point where electron and hole bands touch.