2017/02/01 by Pu Gong, Hongyi Yu, Yong Wang +1 · 32 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Artificial intelligence #Chemistry #Computer science #Crystallography #Dirac (video compression format) #Geology #Hexagonal crystal system #Materials science #Paleontology #Perovskite Materials and Applications #Physics #Quantum mechanics #Rydberg formula #Selection (genetic algorithm) #Series (stratigraphy) #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.95.125420
published in Physical review. B./Physical review. B 95(12) (American Physical Society) · 9 pages, 2 figures
arxiv created 2017/02/01 · openalex created_date 2017/02/17 · openalex publication_date 2017/03/13 · arxiv updated 2017/03/21 · openalex updated_date 2026/08/05
We investigate the optical transition selection rules for excitonic Rydberg series formed in massive Dirac cones. The entanglement of the exciton envelop function with the pseudospin texture leads to anomalous selection rules for one-photon generation of excitons, where d orbitals can be excited with the opposite helicity selection rule from the s orbitals in a given valley. The trigonal warping effects in realistic hexagonal lattices further renders more excited states bright, where p orbitals can also be accessed by one-photon excitation with the opposite valley selection rules to the s orbitals. The one-photon generation of exciton in the various states and the intraexcitonic transition between these states are both dictated by the discrete in-plane rotational symmetry of the lattices, and our results show that in hexagonal 2D materials the symmetry allowed transitions are enabled when trigonal warping effects are included in the massive Dirac fermion model. In monolayer transition metal dichalcogenides where excitons can be generated by visible light and intraexcitonic transitions can be induced by infrared light, we give the strength of these optical transitions, estimated using modified hydrogenlike envelope functions combined with the optical transition matrix elements between the Bloch states calculated at various k points.