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HL: Fachverband Halbleiterphysik
HL 3: Transport: Topological Insulators (jointly with DS, MA, HL, O)
HL 3.12: Talk
Monday, March 20, 2017, 12:30–12:45, HSZ 204
Instability of interaction-driven topological insulators against disorder — Jing Wang1,2, Carmine Ortix1,3, Jeroen van den Brink1, and •Dmitri Efremov1 — 1IFW Dresden, Germany — 2University of Science and Technology of China, Hefei, China — 3Utrecht University, Netherlands
We analyze the effect of disorder on the weak-coupling instabilities of quadratic band crossing point (QBCP) in two-dimensional Fermi systems, which, in the clean limit, display interaction-driven topological insulating phases. In the frame of the weak-coupling renormalization group procedure, which treats fermionic interactions and disorder on the same footing, we test all possible instabilities and identify the corresponding ordered phases in the presence of disorder for both single-valley and two-valley QBCP systems. We find that disorder generally has a strong influence on the stability of the interaction-driven topological insulating phases -- it strongly suppresses the critical temperature at which the topologically non-trivial order sets in -- and can even trigger a phase transition to different, topologically trivial, ordered phases.