Phase Diagram in PbSnSe Topological Quantum Wells*

Topological matter has recently been a wide source of interest as it could provide effective materials for spintronics, quantum information, or ultra fast electronics. Among them, the topological crystalline insulators acquire surface metallic electronic states while their bulk remains insulating. Such surface electrons have the particularity to be two dimension massless Dirac fermions, with a linear dispersion in energy, and are topologically protected against defaults.
The apparition of these surface electronic states have been studied in PbSnSe topological quantum wells. Their description with a k.p theory approach allow us to understand their fundamental origin and to calculate their evolution with the two dimension confinement. The theory ends up with a phase diagram of a topological quantum well.
Preliminary magnetotransport and magneto-optical experiments validate theoretical results.