Nano-imaging of Plasmon polaritons of graphene on SrTiO<sub>3</sub> using terahertz scanning near-field optical microscope
ORAL
Abstract
The electrical and optoelectronic properties of graphene are significantly influenced by the underlying substrate. Replacing the conventional SiO₂/Si substrate with a high-dielectric, atomically smooth ferroelectric substrate such as SrTiO₃ dramatically changes the carrier densities dynamics in graphene. To explore the unique properties of surface plasmon polaritons (SPPs) in graphene on a dielectric substrate, we experimentally apply two advanced imaging techniques: nano-photocurrent mapping in magneto-scanning near-field optical microscopy (m-SNOM) and terahertz time-domain scanning near-field optical microscopy (THz-SNOM) with spacetime metrology. Utilizing THz-SNOM with fine spatial and temporal resolution, we investigate the charge density inhomogeneities and group velocities of SPPs, revealing key insights into the plasmonic behavior of 2D plasmons with a SrTiO₃ substrate.
*M.K.Liu acknowledges Gordon and Betty Moore Foundation DOI: 10.37807/gbmf12258 for supporting the development of polaritonic materials. Research on m-SNOM development is supported as part of Programmable Quantum Materials (Pro-QM), an Energy Frontier Research Center (EFRC) funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. M.K.L. also acknowledges support from the NSF Faculty Early Career Development Program under Grant No. DMR - 2045425.
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Presenters
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Zhenbing Dai
- Stony Brook University (SUNY)