Identification of Tellurium based Phase-Change Materials as Strong Topological Insulators

Phase-change materials (PCMs) [111, 112] are a class of materials which have become of tremendous technological importance over the last two decades. Their ability of a fast and reversible phase transition between an amorphous and crystalline phase makes them appropriate for the application in data storage. PCMs based on Ge-Sb-Te (GST) alloys are characterized by a profound change of optical reflectivity and electrical conductivity upon changing from the amorphous to the crystalline phase [113, 114]. As a consequence, these alloys are already widely used in optical data storage, such as compact discs (CDs) or rewritable digital video discs (DVDs).