Dielectric control of ultrafast carrier dynamics and transport in graphene
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arXiv
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| Autores principales: | , , , , , , |
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| Formato: | Preprint |
| Publicado: |
2026
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| _version_ | 1866911558664192000 |
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| author | Wang, Hai I. Jia, Xiaoyu Nivedan, Anand Bonn, Mischa Cummings, Aron W. Principi, Alessandro Tielrooij, Klaas-Jan |
| author_facet | Wang, Hai I. Jia, Xiaoyu Nivedan, Anand Bonn, Mischa Cummings, Aron W. Principi, Alessandro Tielrooij, Klaas-Jan |
| contents | Understanding the ultrafast dynamics of photoexcited charges in graphene is essential, as the microscopic mechanisms underlying these dynamics determine many of graphene's optical, optothermal, and optoelectronic properties. These are crucial properties for many functionalities and devices enabled by graphene, such as high-speed photodectors. Therefore, beyond scientific understanding, it is highly desirable to control ultrafast carrier dynamics for practical applications. Here, we establish this control by engineering the dielectric environment of graphene, thereby regulating both heating and cooling dynamics without altering the Fermi energy, optical power, or ambient temperature. By combining optical pump-terahertz probe experiments with theoretical calculations, we show that dielectric screening suppresses carrier-carrier interactions and slows the dynamics. In particular, reduced carrier-carrier scattering delays the formation of a quasi-equilibrium hot electron distribution, thus slowing carrier heating. It also slows carrier cooling because re-thermalization after optical-phonon emission depends on the same interactions. The enhanced screening further reduces the energy of electron-hole puddles, thereby increasing charge mobility and the Seebeck coefficient. This ability to externally control internal graphene dynamics and transport properties enables the optimization of device performance, such as the sensitivity of photodetectors for data communication and wireless communication applications. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2604_00217 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Dielectric control of ultrafast carrier dynamics and transport in graphene Wang, Hai I. Jia, Xiaoyu Nivedan, Anand Bonn, Mischa Cummings, Aron W. Principi, Alessandro Tielrooij, Klaas-Jan Mesoscale and Nanoscale Physics Understanding the ultrafast dynamics of photoexcited charges in graphene is essential, as the microscopic mechanisms underlying these dynamics determine many of graphene's optical, optothermal, and optoelectronic properties. These are crucial properties for many functionalities and devices enabled by graphene, such as high-speed photodectors. Therefore, beyond scientific understanding, it is highly desirable to control ultrafast carrier dynamics for practical applications. Here, we establish this control by engineering the dielectric environment of graphene, thereby regulating both heating and cooling dynamics without altering the Fermi energy, optical power, or ambient temperature. By combining optical pump-terahertz probe experiments with theoretical calculations, we show that dielectric screening suppresses carrier-carrier interactions and slows the dynamics. In particular, reduced carrier-carrier scattering delays the formation of a quasi-equilibrium hot electron distribution, thus slowing carrier heating. It also slows carrier cooling because re-thermalization after optical-phonon emission depends on the same interactions. The enhanced screening further reduces the energy of electron-hole puddles, thereby increasing charge mobility and the Seebeck coefficient. This ability to externally control internal graphene dynamics and transport properties enables the optimization of device performance, such as the sensitivity of photodetectors for data communication and wireless communication applications. |
| title | Dielectric control of ultrafast carrier dynamics and transport in graphene |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2604.00217 |