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arXiv · 1901.05250

Magnetic field induced splitting and polarization of monolayer-based valley exciton-polaritons

Nils Lundt·Evgeny Sedov·Max Waldherr·Martin Klaas·Heiko Knopf·Mark Blei·Sefaating Tongay·Sebastian Klembt·Takashi Taniguchi·Kenji Watanabe·Ulrike Schulz·Alexey Kavokin·Sven Höfling·Falk Eilenberger·Christian Schneider
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Abstract

Atomically thin crystals of transition metal dichalcogenides are ideally suited to study the interplay of light-matter coupling, polarization and magnetic field effects. In this work, we investiagte the formation of exciton-polaritons in a MoSe2 monolayer, which is integrated in a fully-grown, monolithic microcavity. Due to the narrow linewidth of the polaritonic resonances, we are able to directly investigate the emerging valley Zeeman splitting of the hybrid light-matter resonances in the presence of a magnetic field. At a detuning of -54.5 meV (13.5 % matter constituent of the lower polariton branch), we find a Zeeman splitting of the lower polariton branch of 0.36 meV, which can be directly associated with an excitonic g factor of 3.94\pm0.13. Remarkably, we find that a magnetic field of 6T is sufficient to induce a notable valley polarization of 15 % in our polariton system, which approaches 30% at 9T. Strikingly, this circular polarization degree of the polariton (ground) state exceeds the polarization of the exciton reservoir for equal magnetic field magnitudes by approximately 50%, as a consequence of enhanced relaxation of bosons in our monolayer-based system.

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Nils Lundt, Evgeny Sedov, Max Waldherr, Martin Klaas, Heiko Knopf, Mark Blei, Sefaating Tongay, Sebastian Klembt, Takashi Taniguchi, Kenji Watanabe, Ulrike Schulz, Alexey Kavokin, Sven Höfling, Falk Eilenberger, Christian Schneider. 2019-01-16. Magnetic field induced splitting and polarization of monolayer-based valley exciton-polaritons. https://doi.org/10.1103/physrevb.100.121303

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