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arXiv · 0904.2117

Merging of Dirac points in a two-dimensional crystal

G. Montambaux·F. Piechon·J. -N. Fuchs·M. O. Goerbig
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Abstract

We study under which general conditions a pair of Dirac points in the electronic spectrum of a two-dimensional crystal may merge into a single one. The merging signals a topological transition between a semi-metallic phase and a band insulator. We derive a universal Hamiltonian that describes the physical properties of the transition, which is controlled by a single parameter, and analyze the Landau-level spectrum in its vicinity. This merging may be observed in the organic salt alpha-(BEDT-TTF)_2 I_3 or in an optical lattice of cold atoms simulating deformed graphene.

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G. Montambaux, F. Piechon, J. -N. Fuchs, M. O. Goerbig. 2009-10-30. Merging of Dirac points in a two-dimensional crystal. https://doi.org/10.1103/physrevb.80.153412

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