Picocavity-Enhanced Raman Spectroscopy of Physisorbed H$_2$ and D$_2$ Molecules

Fuente: arXiv
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Main Authors: Shiotari, Akitoshi, Liu, Shuyi, Trenins, George, Sugimoto, Toshiki, Wolf, Martin, Rossi, Mariana, Kumagai, Takashi
Format: Preprint
Published: 2024
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_version_ 1866908371647463424
author Shiotari, Akitoshi
Liu, Shuyi
Trenins, George
Sugimoto, Toshiki
Wolf, Martin
Rossi, Mariana
Kumagai, Takashi
author_facet Shiotari, Akitoshi
Liu, Shuyi
Trenins, George
Sugimoto, Toshiki
Wolf, Martin
Rossi, Mariana
Kumagai, Takashi
contents We report on tip-enhanced Raman spectroscopy of H2 and D2 molecules physisorbed within a plasmonic picocavity at 10 K. The intense Raman peaks resulting from the rotational and vibrational transitions are observed at subnanometer gap distances of the junction formed by an Ag tip and an Ag(111) surface, where a picocavity-enhanced field plays a crucial role. A significant redshift of the H-H stretch frequency is observed as the gap distance decreases, while the D-D stretch frequency is unaffected. Density functional theory, path-integral molecular dynamics, and quantum anharmonic vibrational energy calculations suggest that this unexpected isotope effect is explained by a different molecular density between H2 and D2 on the surface.
format Preprint
id arxiv_https___arxiv_org_abs_2411_10994
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Picocavity-Enhanced Raman Spectroscopy of Physisorbed H$_2$ and D$_2$ Molecules
Shiotari, Akitoshi
Liu, Shuyi
Trenins, George
Sugimoto, Toshiki
Wolf, Martin
Rossi, Mariana
Kumagai, Takashi
Optics
Mesoscale and Nanoscale Physics
We report on tip-enhanced Raman spectroscopy of H2 and D2 molecules physisorbed within a plasmonic picocavity at 10 K. The intense Raman peaks resulting from the rotational and vibrational transitions are observed at subnanometer gap distances of the junction formed by an Ag tip and an Ag(111) surface, where a picocavity-enhanced field plays a crucial role. A significant redshift of the H-H stretch frequency is observed as the gap distance decreases, while the D-D stretch frequency is unaffected. Density functional theory, path-integral molecular dynamics, and quantum anharmonic vibrational energy calculations suggest that this unexpected isotope effect is explained by a different molecular density between H2 and D2 on the surface.
title Picocavity-Enhanced Raman Spectroscopy of Physisorbed H$_2$ and D$_2$ Molecules
topic Optics
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2411.10994