2023-05-25 ヘルマン・フォン・ヘルムホルツ協会(HGF)
◆この発見は、電子特性を制御し操作する新たな可能性を提供し、高温超伝導などの量子特性を持つ材料の設計に重要な影響を与えると期待されています。これにより、材料工学や量子技術の分野で革新的な応用が可能になるでしょう。
＜関連情報＞
- https://www.helmholtz-berlin.de/pubbin/news_seite?nid=24892&sprache=en&seitenid=1
- https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.023120
炭化チタンのリフシッツ転移はグラフェンのオーバーレイヤーで駆動する Lifshitz transition in titanium carbide driven by a graphene overlayer
M. Krivenkov, D. Marchenko, E. Golias, M. Sajedi, A. S. Frolov, J. Sánchez-Barriga, A. Fedorov, L. V. Yashina, O. Rader, and A. Varykhalov
Physical Review Research Published 25 May 2023
DOI:https://doi.org/10.1103/PhysRevResearch.5.023120
ABSTRACT
Two-dimensional (2D) Dirac materials are electronically and structurally very sensitive to proximity effects. We demonstrate, however, the opposite effect: that the deposition of a monolayer 2D material could exercise a substantial influence on the substrate electronic structure. Here we investigate TiC(111) and show that a graphene overlayer produces a proximity effect, changing the Fermi surface topology of the TiC from six electron pockets to one hole pocket on the depth of several atomic layers inside the substrate. In addition, the graphene electronic structure undergoes an extreme modification as well. While the Dirac cone remains gapless, it experiences an energy shift of 1.0 eV beyond what was recently achieved for the Lifshitz transition of overdoped graphene. Due to this shift, the antibonding π∗ band at the ‾M point becomes occupied and observable by photoemission.
