Observation of charge density wave excitonic order parameter in topological insulator monolayer WTe2
Fuente:
arXiv
Guardado en:
| Autores principales: | , , , , , , , , , , , , , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2025
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866916761708789760 |
|---|---|
| author | Watson, Liam Ripoll, Joan Tong, Zhengjue Kumar, Amit Que, Yande Chan, Yang-Hao Lin, Hsin Mukherjee, Shantanu Garnica, Manuela Edmonds, Mark T. Papaj, Michał de Parga, Amadeo L. Vazquez Weber, Bent Di Bernardo, Iolanda Fuhrer, Michael S. |
| author_facet | Watson, Liam Ripoll, Joan Tong, Zhengjue Kumar, Amit Que, Yande Chan, Yang-Hao Lin, Hsin Mukherjee, Shantanu Garnica, Manuela Edmonds, Mark T. Papaj, Michał de Parga, Amadeo L. Vazquez Weber, Bent Di Bernardo, Iolanda Fuhrer, Michael S. |
| contents | Strong electron-hole interactions in a semimetal or narrow-gap semiconductor may drive a ground state of condensed excitons. Monolayer WTe2 has been proposed as a host material for such an exciton condensate, but the order parameter - the key signature of a macroscopic quantum-coherent condensate - has not been observed. Here we use Fourier-transform scanning tunnelling spectroscopy (FT-STS) to study quasi-particle interference (QPI) and periodic modulations of the local density of states (LDOS) in monolayer WTe2. In WTe2 on graphene, in which the carrier density can be varied via back-gating, FT-STS shows QPI features in the 2D bulk bands, confirming the interacting nature of the bandgap in neutral WTe2 and the semi-metallic nature of highly n- and p-doped WTe2. We observe additional non-dispersive spatial modulations in the LDOS imprinted on the topological edge mode of neutral WTe2 on metallic substrates (graphene and graphite), which we interpret as the interaction of the topological edge mode with the expected charge density wave order parameter of the excitonic condensate in WTe2 at low interaction strength due to screening by the metallic substrates. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2505_20837 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Observation of charge density wave excitonic order parameter in topological insulator monolayer WTe2 Watson, Liam Ripoll, Joan Tong, Zhengjue Kumar, Amit Que, Yande Chan, Yang-Hao Lin, Hsin Mukherjee, Shantanu Garnica, Manuela Edmonds, Mark T. Papaj, Michał de Parga, Amadeo L. Vazquez Weber, Bent Di Bernardo, Iolanda Fuhrer, Michael S. Strongly Correlated Electrons Mesoscale and Nanoscale Physics Strong electron-hole interactions in a semimetal or narrow-gap semiconductor may drive a ground state of condensed excitons. Monolayer WTe2 has been proposed as a host material for such an exciton condensate, but the order parameter - the key signature of a macroscopic quantum-coherent condensate - has not been observed. Here we use Fourier-transform scanning tunnelling spectroscopy (FT-STS) to study quasi-particle interference (QPI) and periodic modulations of the local density of states (LDOS) in monolayer WTe2. In WTe2 on graphene, in which the carrier density can be varied via back-gating, FT-STS shows QPI features in the 2D bulk bands, confirming the interacting nature of the bandgap in neutral WTe2 and the semi-metallic nature of highly n- and p-doped WTe2. We observe additional non-dispersive spatial modulations in the LDOS imprinted on the topological edge mode of neutral WTe2 on metallic substrates (graphene and graphite), which we interpret as the interaction of the topological edge mode with the expected charge density wave order parameter of the excitonic condensate in WTe2 at low interaction strength due to screening by the metallic substrates. |
| title | Observation of charge density wave excitonic order parameter in topological insulator monolayer WTe2 |
| topic | Strongly Correlated Electrons Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2505.20837 |