Energy bands in solids describe quantum states in periodic crystals. When a quantum state is wound around the Brillouin zone, it acquires a quantum phase. For a completely filled band, the global phase acquired in this winding is a topological property of the band. For 3D solid with timereversal symmetry, there are two topological classes corresponding to a ±1 sign. A signature of topological solids (minus sign) is the presence of conducting surface states with a relativistic dispersion, similar to graphene. They can be observed in angle resolved photo-emission which is able to reconstruct their energy-momentum dispersion below the Fermi level. Some of the experimental signatures of these topological states in strained Mercury-Telluride are presented: their Dirac spectra measured at the SOLEIL synchrotron, the ambipolar sign of their surface charge carriers, the topological phase in their Landau-level quantization, and the weak-antilocalization peak in magnetotransport also controlled by the π-topological phase.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
Bitte loggen Sie sich ein, um Zugang zu diesem Inhalt zu erhalten
Sie möchten Zugang zu diesem Inhalt erhalten? Dann informieren Sie sich jetzt über unsere Produkte:
- Experimental Signatures of Topological Insulators