Optical signatures of charge order in a Mott-Wigner state

Yuya Shimazaki; Clemens Kuhlenkamp; Ido Schwartz; Tomasz Smolenski; Kenji Watanabe; Takashi Taniguchi; Martin Kroner; Richard Schmidt; Michael Knap; Atac Imamoglu

doi:10.1103/physrevx.11.021027

arXiv · 2008.04156

Optical signatures of charge order in a Mott-Wigner state

Yuya Shimazaki·Clemens Kuhlenkamp·Ido Schwartz·Tomasz Smolenski·Kenji Watanabe·Takashi Taniguchi·Martin Kroner·Richard Schmidt·Michael Knap·Atac Imamoglu

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Abstract

The elementary optical excitations in two dimensional semiconductors hosting itinerant electrons are attractive and repulsive polarons -- excitons that are dynamically screened by electrons. Exciton-polarons have hitherto been studied in translationally invariant degenerate Fermi systems. Here, we show that electronic charge order breaks the excitonic translational invariance and leads to a direct optical signature in the exciton-polaron spectrum. Specifically, we demonstrate that new optical resonances appear due to spatially modulated interaction between excitons and electrons in an incompressible Mott state. Our observations demonstrate that resonant optical spectroscopy provides an invaluable tool for studying strongly correlated states, such as Wigner crystals and density waves, where exciton-electron interactions are modified by the emergence of new electronic charge or spin order.

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Yuya Shimazaki, Clemens Kuhlenkamp, Ido Schwartz, Tomasz Smolenski, Kenji Watanabe, Takashi Taniguchi, Martin Kroner, Richard Schmidt, Michael Knap, Atac Imamoglu. 2020-09-29. Optical signatures of charge order in a Mott-Wigner state. https://doi.org/10.1103/physrevx.11.021027

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