Topological phase transition in bulk materials described by the coherent potential approximation technique

We consider the analogy between the topological phase transition which occurs on a surface of a non-trivial insulator as a function of spatial coordinate, and the phase transition occurring in the bulk due to the change of internal parameters (such as crystal field and spin-orbit coupling). In both cases the system exhibits a Dirac cone, which is the universal manifestation of a topological phase transition, independent of the type of the driving parameters. In particular, this leads to a simple way of determining the topological class - based solely on the bulk information - even for systems where the translational symmetry is broken by atomic disorder or by strong electron correlations. Here we demonstrate this idea, using as an example the zinc-blende related semiconductors by means of ab-initio fully-relativistic band structure calculations, involving the technique of coherent potential approximation (CPA). (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim