Ultrafast Electronic Band Gap Control in an Excitonic Insulator
- We report on the nonequilibrium dynamics of the electronic structure of the layered semiconductor Ta2NiSe5 investigated by time-and angle-resolved photoelectron spectroscopy. We show that below the critical excitation density of F-C = 0.2 mJ cm(-2), the band gap narrows transiently, while it is enhanced above FC. Hartree-Fock calculations reveal that this effect can be explained by the presence of the low-temperature excitonic insulator phase of Ta2NiSe5, whose order parameter is connected to the gap size. This work demonstrates the ability to manipulate the band gap of Ta2NiSe5 with light on the femtosecond time scale.
| Author details: | Selene Mor, Marc HerzogORCiDGND, Denis Golez, Philipp Werner, Martin Eckstein, Naoyuki Katayama, Minoru Nohara, Hide Takagi, Takashi Mizokawa, Claude Monney, Julia Staehler |
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| DOI: | https://doi.org/10.1103/PhysRevLett.119.086401 |
| ISSN: | 0031-9007 |
| ISSN: | 1079-7114 |
| Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/28952776 |
| Title of parent work (English): | Physical review letters |
| Publisher: | American Physical Society |
| Place of publishing: | College Park |
| Publication type: | Article |
| Language: | English |
| Year of first publication: | 2017 |
| Publication year: | 2017 |
| Release date: | 2020/04/20 |
| Volume: | 119 |
| Number of pages: | 5 |
| First page: | 11559 |
| Last Page: | 11567 |
| Funding institution: | ERC Starting Grant [278023]; ERC Consolidator Grant [724103]; SNSF Grant [200021-140648, PZ00P2_154867] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| Peer review: | Referiert |
