Do magnons play a role in excitonic nonlinearity of van der Waals magnets?

ORAL

Abstract

Excitons are quasiparticles that can significantly alter the optical properties of semiconductors. Interacting excitons can lead to large optical nonlinearity and various emergent phases of matter. These interactions are commonly driven by exchange interactions or phase space filling. Here, we study previously unexplored mechanisms for excitonic interactions possible in correlated materials with excitons coupled to other degrees of freedom. Specifically, we demonstrate that in CrSBr, an antiferromagnetic semiconductor, magnons mediate excitonic interactions, leading to pronounced optical nonlinearity. Magnons and excitons typically remain independent due to their differing energy scales. However, our study reveals an exciton-density-dependent energy shift facilitated by a magnonic adjustment of the spin canting angle. Our theoretical model accurately captures how the strong exciton-magnon coupling leads to magnon-mediated exciton interactions. Additionally, we identify distinct nonlinear responses between the two types of excitons, A and B, in CrSBr, which stem from their different magneto-optical characteristics. This work highlights the emergence of quasiparticle-mediated interactions in correlated quantum materials, leading to large nonlinear optical responses and enabling novel device concepts, such as magnon-mediated quantum transducers.



Funding: Gordon and Betty Moore Foundation (Grant No. 12764), Army Research Office (W911NF-23-1-0394), and NSF (2216838).

*The work is supported by the Gordon and Betty Moore Foundation (Grant No. 12764), the Army Research Office (W911NF-23-1-0394), and NSF (2216838).

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Publication: Biswajit Datta, et al. Magnon-mediated exciton-exciton interaction in a van der Waals antiferromagnet. Preprint at arXiv:2409.18501 (2024).

Presenters

  • Pratap C Adak

    • City College of New York

Authors

  • Pratap C Adak

    • City College of New York

  • Biswajit Datta

    • City College of New York

  • Sichao Yu

    • The City University of New York

  • Agneya V Dharmapalan

    • The Graduate Center, City University of New York
    • City College of New York, New York, NY 10031, USA

  • Siedah J Hall

    • CUNY
    • Advanced Science Research Center (ASRC), CUNY

  • Anton Vakulenko

    • University of Central Florida, Orlando, Florida 32816, USA

  • Filipp Komissarenko

    • The City College of New York, New York, NY 10031, USA

  • Egor Kurganov

    • University of Central Florida, Orlando, Florida 32816, USA

  • Jiamin Quan

    • The Graduate Center, City University of New York

  • Wei Wang

    • Graduate Center of the City University of New York (CUNY), New York, NY 10016, USA

  • Kseniia Mosina

    • University of Chemistry and Technology Prague

  • Zdenek Sofer

    • University of Chemistry and Technology Prague
    • Department of Inorganic Chemistry, University of Chemistry and Technology Prague

  • Dimitar Pashov

    • King's College London
    • King's College London, The Strand, London WC2R2LS, UK

  • Mark van Schilfgaarde

    • National Renewable Energy Laboratory
    • National Renewable Energy Laboratory, Golden, Colorado 80401, USA

  • Swagata Acharya

    • National Renewable Energy Laboratory (NREL)

  • Akashdeep Kamra

    • Condensed Matter Physics Center (IFIMAC) and Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid
    • Rheinland-Pfälzische Technische Universität (RPTU), Kaiserslautern-Landau, Kaiserslautern, Germany.

  • Matthew Y Sfeir

    • The Graduate Center, City University of New York

  • Andrea Alu

    • The Graduate Center, City University of New York

  • Alexander Khanikaev

    • City College of New York

  • Vinod Menon

    • City College & Grad Center of CUNY
    • City College of New York