Pseudospins revealed through the giant dynamical Franz-Keldysh effect in massless Dirac materials

Fuente: arXiv
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Main Author: Kim, Youngjae
Format: Preprint
Published: 2024
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author Kim, Youngjae
author_facet Kim, Youngjae
contents The dynamical Franz-Keldysh effect, indicative of the transient light-matter interaction regime between quantum and classical realms, is widely recognized as an essential signature in wide bandgap condensed matter systems such as dielectrics. In this study, we applied the time-resolved transient absorption spectroscopy to investigate ultrafast optical responses in graphene, a zero-bandgap system. We observed in the gate-tuned graphene that the massless Dirac materials notably enhance intraband light-driven transitions, significantly leading to the giant dynamical Franz-Keldysh effect compared to the massive Dirac materials, a wide bandgap system. In addition, employing the angle-resolved spectroscopy, it is found that the unique polarimetry orientation, i.e., perpendicular polarizations for the pump and the probe, further pronounces the optical spectra to exhibit the complete fishbone structure, reflecting the quantum pseudospin nature of Dirac cones. Our findings expand the establishment of emergent transient spectroscopy frameworks into not only zero-bandgap systems but also pseudospin-mediated quantum phenomena, moving beyond dielectrics.
format Preprint
id arxiv_https___arxiv_org_abs_2401_16898
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Pseudospins revealed through the giant dynamical Franz-Keldysh effect in massless Dirac materials
Kim, Youngjae
Mesoscale and Nanoscale Physics
Materials Science
Strongly Correlated Electrons
Optics
The dynamical Franz-Keldysh effect, indicative of the transient light-matter interaction regime between quantum and classical realms, is widely recognized as an essential signature in wide bandgap condensed matter systems such as dielectrics. In this study, we applied the time-resolved transient absorption spectroscopy to investigate ultrafast optical responses in graphene, a zero-bandgap system. We observed in the gate-tuned graphene that the massless Dirac materials notably enhance intraband light-driven transitions, significantly leading to the giant dynamical Franz-Keldysh effect compared to the massive Dirac materials, a wide bandgap system. In addition, employing the angle-resolved spectroscopy, it is found that the unique polarimetry orientation, i.e., perpendicular polarizations for the pump and the probe, further pronounces the optical spectra to exhibit the complete fishbone structure, reflecting the quantum pseudospin nature of Dirac cones. Our findings expand the establishment of emergent transient spectroscopy frameworks into not only zero-bandgap systems but also pseudospin-mediated quantum phenomena, moving beyond dielectrics.
title Pseudospins revealed through the giant dynamical Franz-Keldysh effect in massless Dirac materials
topic Mesoscale and Nanoscale Physics
Materials Science
Strongly Correlated Electrons
Optics
url https://arxiv.org/abs/2401.16898