Dresden 2017 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 70: Topological Insulators I (joined session with TT)
HL 70.2: Talk
Thursday, March 23, 2017, 10:00–10:15, POT 251
2D Topological Insulators: Trends in Chemical Space — •Carlos Mera Acosta1,2, Christian Carbogno1, Adalberto Fazzio2, Luca M. Ghiringhelli1, and Matthias Scheffler1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin — 2Instituto de Física, Universidade de São Paulo, SP, Brazil
2D topological insulators (TI) have attracted considerable scientific interest in recent years [1]. The search for new TIs has often focused on elements with strong spin-orbit coupling (SOC) [2], which can induce the necessary topological transition. In this work, we have computed the topological invariant Z2 for 200 functionalized honeycomb-lattice systems using our recent Wannier center of charge (WCC) [3] implementation in the FHI-aims electronic structure code. Besides confirming the TI character of well-known materials, e.g., functionalized stanene [1], our study found several other yet unreported TIs. This reveals that also elements with relatively low SOC can form TIs. To analyze the observed trends in chemical space we relate the WCCs to the atomic features of the constituent atoms using a compressed-sensing approach. For this purpose, the LASSO and ℓ0 minimization of Ref. [4] is extended from learning scalar properties to functions.
This work received funding from The Novel Materials Discovery (NOMAD) Laboratory, a European Centre of Excellence.
[1] Y. Ren, Z. Qiao, and Q. Niu, RPP 79, 6 66501 (2016).
[2] M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82, 3045 (2010).
[3] R. Yu, et al., Phys. Rev. B 84, 075119 (2011).
[4] L. M. Ghirighelli, et al., Phys. Rev. Lett. 114, 105503 (2015).