Unconventional charge-density-wave gap in monolayer NbS$_2$
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2023
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866909106704482304 |
|---|---|
| author | Knispel, Timo Berges, Jan Schobert, Arne van Loon, Erik G. C. P. Jolie, Wouter Wehling, Tim Michely, Thomas Fischer, Jeison |
| author_facet | Knispel, Timo Berges, Jan Schobert, Arne van Loon, Erik G. C. P. Jolie, Wouter Wehling, Tim Michely, Thomas Fischer, Jeison |
| contents | Using scanning tunneling microscopy and spectroscopy, for a monolayer of transition metal dichalcogenide H-NbS$_2$ grown by molecular beam epitaxy on graphene, we provide unambiguous evidence for a charge density wave (CDW) with a 3$\times$3 superstructure, which is not present in bulk NbS$_2$. Local spectroscopy displays a pronounced gap of the order of 20 meV at the Fermi level. Within the gap low energy features are present. The gap structure with its low energy features is at variance with the expectation for a gap opening in the electronic band structure due to a CDW. Instead, comparison with \it{ab initio} calculations indicates that the observed gap structure must be attributed to combined electron-phonon quasiparticles. The phonons in question are the elusive amplitude and phase collective modes of the CDW transition. Our findings advance the understanding of CDW mechanisms in two dimensional materials and their spectroscopic signatures. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2307_13791 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Unconventional charge-density-wave gap in monolayer NbS$_2$ Knispel, Timo Berges, Jan Schobert, Arne van Loon, Erik G. C. P. Jolie, Wouter Wehling, Tim Michely, Thomas Fischer, Jeison Mesoscale and Nanoscale Physics Materials Science Strongly Correlated Electrons Using scanning tunneling microscopy and spectroscopy, for a monolayer of transition metal dichalcogenide H-NbS$_2$ grown by molecular beam epitaxy on graphene, we provide unambiguous evidence for a charge density wave (CDW) with a 3$\times$3 superstructure, which is not present in bulk NbS$_2$. Local spectroscopy displays a pronounced gap of the order of 20 meV at the Fermi level. Within the gap low energy features are present. The gap structure with its low energy features is at variance with the expectation for a gap opening in the electronic band structure due to a CDW. Instead, comparison with \it{ab initio} calculations indicates that the observed gap structure must be attributed to combined electron-phonon quasiparticles. The phonons in question are the elusive amplitude and phase collective modes of the CDW transition. Our findings advance the understanding of CDW mechanisms in two dimensional materials and their spectroscopic signatures. |
| title | Unconventional charge-density-wave gap in monolayer NbS$_2$ |
| topic | Mesoscale and Nanoscale Physics Materials Science Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2307.13791 |