Unconventional Charge-Density-Wave Gap in Monolayer NbS2
(2024) In Nano Letters 24(4). p.1045-1051- Abstract
- Using scanning tunneling microscopy and spectroscopy, for a monolayer of transition metal dichalcogenide H-NbS2 grown by molecular beam epitaxy on graphene, we provide unambiguous evidence for a charge density wave (CDW) with a 3 × 3 superstructure, which is not present in bulk NbS2. Local spectroscopy displays a pronounced gap on 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 ab initio calculations indicates that the observed gap structure must be attributed to combined electron–phonon quasiparticles. The... (More)
- Using scanning tunneling microscopy and spectroscopy, for a monolayer of transition metal dichalcogenide H-NbS2 grown by molecular beam epitaxy on graphene, we provide unambiguous evidence for a charge density wave (CDW) with a 3 × 3 superstructure, which is not present in bulk NbS2. Local spectroscopy displays a pronounced gap on 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 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 2D materials and their spectroscopic signatures. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/b9cfffcc-0367-4ed9-a98c-6f78fcc6c6dc
- author
- Knispel, Timo ; Berges, Jan ; Schobert, Arne ; van Loon, Erik G. C. P. LU ; Jolie, Wouter ; Wehling, T. O. ; Michely, Thomas and Fischer, Jeison
- organization
- publishing date
- 2024-01-31
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Nano Letters
- volume
- 24
- issue
- 4
- pages
- 6 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:38232959
- scopus:85183484204
- ISSN
- 1530-6992
- DOI
- 10.1021/acs.nanolett.3c02787
- project
- Correlated materials beyond dynamical mean-field theory
- language
- English
- LU publication?
- yes
- id
- b9cfffcc-0367-4ed9-a98c-6f78fcc6c6dc
- date added to LUP
- 2024-02-01 12:13:23
- date last changed
- 2024-02-15 10:37:26
@article{b9cfffcc-0367-4ed9-a98c-6f78fcc6c6dc, abstract = {{Using scanning tunneling microscopy and spectroscopy, for a monolayer of transition metal dichalcogenide H-NbS<sub>2</sub> grown by molecular beam epitaxy on graphene, we provide unambiguous evidence for a charge density wave (CDW) with a 3 × 3 superstructure, which is not present in bulk NbS<sub>2</sub>. Local spectroscopy displays a pronounced gap on 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 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 2D materials and their spectroscopic signatures.}}, author = {{Knispel, Timo and Berges, Jan and Schobert, Arne and van Loon, Erik G. C. P. and Jolie, Wouter and Wehling, T. O. and Michely, Thomas and Fischer, Jeison}}, issn = {{1530-6992}}, language = {{eng}}, month = {{01}}, number = {{4}}, pages = {{1045--1051}}, publisher = {{The American Chemical Society (ACS)}}, series = {{Nano Letters}}, title = {{Unconventional Charge-Density-Wave Gap in Monolayer NbS<sub>2</sub>}}, url = {{http://dx.doi.org/10.1021/acs.nanolett.3c02787}}, doi = {{10.1021/acs.nanolett.3c02787}}, volume = {{24}}, year = {{2024}}, }