Topological nanostructures with halide perovskites Alexander - PowerPoint PPT Presentation

Topological nanostructures with halide perovskites Alexander Berestennikov berestennikov.alex@gmail.com METANANO 2020

Halide perovskites • Simple fabrication • Easy processing • High refractive index (n = 2-3) • Chemically tunable bandgap • Strong optical nonlinear response • High defect tolerance 2

Topology and topological insulators The concept of topological insulators Hasan, Kane. Rev. Mod. Phys. 82 , 3045 (2010)

Photonic crystals Periodically stacking materials with different dielectric or magnetic properties to the “infinite” structure Joannopoulos, J. D., Johnson, S. G., Winn, J. N. & Meade, R. D., Photonic Crystals: Molding the Flow of Light, 2nd ed. (Princeton University Press, Princeton , 2008)

Topological models • Su-Schrieffer-Heeger 2 4 5 6 7 1 model Energy spectrum Field distribution for the edge mode Su, Schrieffer, Heeger. Physical Review Letters, 42 (25), P. 1698 – 1701 ( 1979 ) Realized in electronic, photonic, plasmonic, polaritonic and mechanical systems Experimental observation: [1] N. Malkova, et al . Optics Letters, vol. 34, 1633 (2009). [2] Sinev, et al . Nanoscale 7, 11904 (2015). [3] Blanco-Redondo, et al . Phys. Rev. Lett. 116, 163901 (2016).

Topological hybrid silicon microlasers Non-Hermitian variant of the paradigmatic Su-Schrieffer-Heeger (SSH) model The coupling profile is precisely controlled by the separations between adjacent rings Han Zhao et al., Nat. Comm. 9, 981 (2018)

Silicon Kagome lattice with perovskite QDs Thickness: 70 nm +20nm layer (n=2.5) 708 нм 705 нм 701 нм Q = 22 Q = 21 Q = 30 13 ячеек

Darkfield scattering 635 nm 645 nm 102 d1-2 big triangle 300 102 d1-2 center 102 d1-2 corner 250 200 150 100 50 0 -50 550 600 650 700 750 800 620 nm 615 nm 625 nm

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