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DOE OSTI · 1874067

Surface plasmons induce topological transition in graphene/α-MoO3 heterostructures

Ruta, Francesco L. (ORCID:0000000287469420)·Kim, Brian S. Y. (ORCID:0000000230244220)·Sun, Zhiyuan (ORCID:0000000203426248)·Rizzo, Daniel J. (ORCID:0000000345874863)·McLeod, Alexander S. (ORCID:000000025232634X)·Rajendran, Anjaly·Liu, Song·Millis, Andrew J.·Hone, James C. (ORCID:0000000280843301)·Basov, D. N. (ORCID:0000000197855387)
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Abstract

Abstract Polaritons in hyperbolic van der Waals materials—where principal axes have permittivities of opposite signs—are light-matter modes with unique properties and promising applications. Isofrequency contours of hyperbolic polaritons may undergo topological transitions from open hyperbolas to closed ellipse-like curves, prompting an abrupt change in physical properties. Electronically-tunable topological transitions are especially desirable for future integrated technologies but have yet to be demonstrated. In this work, we present a doping-induced topological transition effected by plasmon-phonon hybridization in graphene/α-MoO 3 heterostructures. Scanning near-field optical microscopy was used to image hybrid polaritons in graphene/α-MoO 3 . We demonstrate the topological transition and characterize hybrid modes, which can be tuned from surface waves to bulk waveguide modes, traversing an exceptional point arising from the anisotropic plasmon-phonon coupling. Graphene/α-MoO 3 heterostructures offer the possibility to explore dynamical topological transitions and directional coupling that could inspire new nanophotonic and quantum devices.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICSmetamaterialsoptical properties and devicespolaritonsscanning probe microscopysub-wavelength optics

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Ruta, Francesco L. (ORCID:0000000287469420), Kim, Brian S. Y. (ORCID:0000000230244220), Sun, Zhiyuan (ORCID:0000000203426248), Rizzo, Daniel J. (ORCID:0000000345874863), McLeod, Alexander S. (ORCID:000000025232634X), Rajendran, Anjaly, Liu, Song, Millis, Andrew J., Hone, James C. (ORCID:0000000280843301), Basov, D. N. (ORCID:0000000197855387). 2022-06-28. Surface plasmons induce topological transition in graphene/α-MoO3 heterostructures. https://doi.org/10.1038/s41467-022-31477-z

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