Hyperbolic exciton polaritons in a van der Waals magnet

© 2023. The Author(s)..

Exciton polaritons are quasiparticles of photons coupled strongly to bound electron-hole pairs, manifesting as an anti-crossing light dispersion near an exciton resonance. Highly anisotropic semiconductors with opposite-signed permittivities along different crystal axes are predicted to host exotic modes inside the anti-crossing called hyperbolic exciton polaritons (HEPs), which confine light subdiffractionally with enhanced density of states. Here, we show observational evidence of steady-state HEPs in the van der Waals magnet chromium sulfide bromide (CrSBr) using a cryogenic near-infrared near-field microscope. At low temperatures, in the magnetically-ordered state, anisotropic exciton resonances sharpen, driving the permittivity negative along one crystal axis and enabling HEP propagation. We characterize HEP momentum and losses in CrSBr, also demonstrating coupling to excitonic sidebands and enhancement by magnetic order: which boosts exciton spectral weight via wavefunction delocalization. Our findings open new pathways to nanoscale manipulation of excitons and light, including routes to magnetic, nonlocal, and quantum polaritonics.

Errataetall:

ErratumIn: Nat Commun. 2024 Feb 27;15(1):1795. - PMID 38413595

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:14

Enthalten in:

Nature communications - 14(2023), 1 vom: 13. Dez., Seite 8261

Sprache:

Englisch

Beteiligte Personen:

Ruta, Francesco L [VerfasserIn]
Zhang, Shuai [VerfasserIn]
Shao, Yinming [VerfasserIn]
Moore, Samuel L [VerfasserIn]
Acharya, Swagata [VerfasserIn]
Sun, Zhiyuan [VerfasserIn]
Qiu, Siyuan [VerfasserIn]
Geurs, Johannes [VerfasserIn]
Kim, Brian S Y [VerfasserIn]
Fu, Matthew [VerfasserIn]
Chica, Daniel G [VerfasserIn]
Pashov, Dimitar [VerfasserIn]
Xu, Xiaodong [VerfasserIn]
Xiao, Di [VerfasserIn]
Delor, Milan [VerfasserIn]
Zhu, X-Y [VerfasserIn]
Millis, Andrew J [VerfasserIn]
Roy, Xavier [VerfasserIn]
Hone, James C [VerfasserIn]
Dean, Cory R [VerfasserIn]
Katsnelson, Mikhail I [VerfasserIn]
van Schilfgaarde, Mark [VerfasserIn]
Basov, D N [VerfasserIn]

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Date Revised 01.03.2024

published: Electronic

ErratumIn: Nat Commun. 2024 Feb 27;15(1):1795. - PMID 38413595

Citation Status PubMed-not-MEDLINE

doi:

10.1038/s41467-023-44100-6

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM36577572X