Regensburg 2013 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 61: Topological Insulators 4 (jointly with DS, HL, MA, and O)

TT 61.8: Vortrag

Donnerstag, 14. März 2013, 17:15–17:30, H18

Probing the Band Topology of Mercury Telluride through Weak Localization and Antilocalization — •Viktor Krueckl and Klaus Richter — Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg

We investigate the effect of weak localization (WL) and weak antilocalization (WAL) in the diffusive transport through HgTe/CdTe quantum wells. Our results reveal different transitions between WL and WAL depending on the Fermi energy as well as the band topology [1]. If spin-orbit interactions from bulk and structure inversion asymmetry can be neglected, the magnetoconductance of a system with inverted band ordering features a transition from WL to WAL and back. This is a signature of the Berry phase arising for inverted band ordering and not present in heterostructures with conventional ordering. In presence of strong spin-orbit interaction both band topologies exhibit WAL, which is distinctly energy dependent solely for quantum wells with inverted band ordering. This can be explained by an energy-dependent decomposition of the Hamiltonian into two blocks.
[1] V. Krueckl and K. Richter, Semicond. Sci. Technol. 27, 124006 (2012)