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arXiv · 1902.09342

Generic optical excitations of correlated systems: $π$-tons

Anna Kauch·Petra Pudleiner·Katharina Astleithner·Patrik Thunström·Tin Ribic·Karsten Held
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Abstract

The interaction of light with solids gives rise to new bosonic quasiparticles, with the exciton being---undoubtedly---the most famous of these polaritons. While excitons are the generic polaritons of semiconductors, we show that for strongly correlated systems another polariton is prevalent---originating from the dominant antiferromagnetic or charge density wave fluctuations in these systems. As these are usually associated with a wave vector ${\mathbf k}= (π,π,\ldots)$ or close to it, we propose to call the derived polaritons $π$-tons. These $π$-tons yield the leading vertex correction to the optical conductivity in all correlated models studied: the Hubbard, the extended Hubbard model, the Falicov-Kimball, and the Pariser-Parr-Pople model, both in the insulating and in the metallic phase.

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Anna Kauch, Petra Pudleiner, Katharina Astleithner, Patrik Thunström, Tin Ribic, Karsten Held. 2020-02-03. Generic optical excitations of correlated systems: $π$-tons. https://doi.org/10.1103/physrevlett.124.047401

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