Engineering anisotropic electrodynamics at the graphene/CrSBr interface
Graphene is a privileged 2D platform for hosting confined light-matter excitations known as surface plasmon polaritons (SPPs), as it possesses low intrinsic losses and a high degree of optical confinement. However, the isotropic nature of graphene limits its ability to guide and focus SPPs, making it less suitable than anisotropic elliptical and hyperbolic materials for polaritonic lensing and canalization. Here, we present graphene/CrSBr as an engineered 2D interface that hosts highly anisotropic SPP propagation across mid-infrared and terahertz energies. Using scanning tunneling microscopy, scattering-type scanning near-field optical microscopy, and first-principles calculations, we demonstrate mutual doping in excess of 10<sup>13 </sup>cm<sup>-2</sup> holes/electrons between the interfacial layers of graphene/CrSBr. SPPs in graphene activated by charge transfer interact with charge-induced electronic anisotropy in the interfacial doped CrSBr, leading to preferential SPP propagation along the quasi-1D chains that compose each CrSBr layer. This multifaceted proximity effect both creates SPPs and endows them with anisotropic propagation lengths that differ by an order-of-magnitude between the in-plane crystallographic axes of CrSBr.
Authors
- P. James Schuck (ORCID: https://orcid.org/0000-0001-9244-2671)
- Yinming Shao (ORCID: https://orcid.org/0000-0002-2891-0028)
- Kaichen Xie (ORCID: https://orcid.org/0000-0001-8479-8301)
- Evan J. Telford (ORCID: https://orcid.org/0000-0002-9494-9166)
- Thomas P. Darlington (ORCID: https://orcid.org/0000-0002-3498-3936)
- Matthew Strasbourg (ORCID: https://orcid.org/0009-0007-8062-1075)
- Aravind Devarakonda (ORCID: https://orcid.org/0000-0002-6095-7854)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- D. N. Basov (ORCID: https://orcid.org/0000-0001-9785-5387)
- Sara Shabani (ORCID: https://orcid.org/0000-0002-9524-9380)
- Fangzhou Zhao (ORCID: https://orcid.org/0000-0001-7355-7406)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Jordan M. Cox (ORCID: https://orcid.org/0000-0003-4266-0990)
- Francesco L. Ruta (ORCID: https://orcid.org/0000-0002-8746-9420)
- Abhay N. Pasupathy (ORCID: https://orcid.org/0000-0002-2744-0634)
- Daniel G. Chica (ORCID: https://orcid.org/0000-0001-8616-9365)
- Rocco A. Vitalone (ORCID: https://orcid.org/0000-0002-9009-4092)
- Ting Cao (ORCID: https://orcid.org/0000-0003-1300-6084)
- Daniel J. Rizzo (ORCID: https://orcid.org/0000-0003-4587-4863)
- Siyuan Qiu
- Cory R. Dean (ORCID: https://orcid.org/0000-0003-2967-5960)
- Xavier Roy (ORCID: https://orcid.org/0000-0002-8850-0725)
- Suheng Xu (ORCID: https://orcid.org/0000-0002-1456-5489)
- Eric Seewald (ORCID: https://orcid.org/0000-0001-8803-4720)
- Andrew J. Millis (ORCID: https://orcid.org/0000-0001-9413-6344)
- Ángel Rubio (ORCID: https://orcid.org/0000-0003-2060-3151)
- Xiaoyang Zhu (ORCID: https://orcid.org/0000-0002-2090-8484)
Institutions
- Pennsylvania State University (US)
- Universität Hamburg (DE)
- University of the Basque Country (ES)
- University of Washington (US)
- National Institute for Materials Science (JP)
- Center for Free-Electron Laser Science (DE)
- Max Planck Institute for the Structure and Dynamics of Matter (DE)
- Flatiron Health (United States) (US)
- Columbia University (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-02-21
- DOI
- https://doi.org/10.1038/s41467-025-56804-y
- Citations
- 13
- Primary Topic
- Plasmonic and Surface Plasmon Research
- Type
- article
- Field-Weighted Citation Impact
- 8.76