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arXiv · 2007.08282

Dominant Role of Two-Photon Vertex in Nonlinear Response of Dirac Materials

Habib Rostami·Emmanuele Cappelluti
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Abstract

Using a conserving Baym-Kadanoff approach, we present a fully compelling theory of nonlinear dc response of a Dirac system to electric fields in the presence of disorder scattering. We show that the nonlinear terms are strikingly ruled by the appearance of a dominant two-photon vertex which is absent at the bare level and finite even in the weak-coupling limit. Such two-photon vertex self-generation highlights the crucial role of the frequency and field dependence of the scattering rates in the nonlinear regime. Our study reveals a novel many-body mechanism in the nonlinear response of Dirac materials whose effects are predicted to be observable.

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Habib Rostami, Emmanuele Cappelluti. 2020-07-16. Dominant Role of Two-Photon Vertex in Nonlinear Response of Dirac Materials. https://doi.org/10.1038/s41699-021-00217-0

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