Photo-excitation band-structure engineering of 2H-NbSe$_2$ probed by time- and angle-resolved photoemission spectroscopy
J. Phys. Soc. Jpn. 91, 064703 (2022) We investigated the nonequilibrium electronic structure of 2H-NbSe$_2$ by time- and angle-resolved photoemission spectroscopy. We find that the band structure is distinctively modulated by strong photo-excitation, as indicated by the unusual increase in the photo...
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Main Authors | , , , , , , , , , , |
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Format | Journal Article |
Language | English |
Published |
07.10.2020
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Subjects | |
Online Access | Get full text |
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Summary: | J. Phys. Soc. Jpn. 91, 064703 (2022) We investigated the nonequilibrium electronic structure of 2H-NbSe$_2$ by
time- and angle-resolved photoemission spectroscopy. We find that the band
structure is distinctively modulated by strong photo-excitation, as indicated
by the unusual increase in the photoelectron intensities around E$_F$. In order
to gain insight into the observed photo-induced electronic state, we performed
DFT calculations with modulated lattice structures, and found that the
variation of the Se height from the Nb layer results in a significant change in
the effective mass and band gap energy. We further study the momentum-dependent
carrier dynamics. The results suggest that the relaxation is faster at the
K-centered Fermi surface than at the $\Gamma$-centered Fermi surface, which can
be attributed to the stronger electron-lattice coupling at the K-centered Fermi
surface. Our demonstration of band structure engineering suggests a new role
for light as a tool for controlling the functionalities of solid-state
materials. |
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DOI: | 10.48550/arxiv.2010.03751 |