Emergence of monolayer electron behavior in bulk van der Waals superlattice

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Pengfei Ding - , Renmin University of China (Author)
  • Jun Fa Lin - , Renmin University of China (Author)
  • Peihan Sun - , Hebei University of Science and Technology (Author)
  • Rui Lou - , Leibniz Institute for Solid State and Materials Research Dresden, Helmholtz Centre Berlin for Materials and Energy (Author)
  • Alexander Fedorov - , Leibniz Institute for Solid State and Materials Research Dresden, Helmholtz Centre Berlin for Materials and Energy (Author)
  • Zhi Xiao He - , Renmin University of China (Author)
  • Huan Ma - , Renmin University of China (Author)
  • Zuoping Zhou - , Tsinghua University (Author)
  • Bernd Büchner - , Clusters of Excellence ct.qmat: Complexity and Topology in Quantum Matter, Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Xi Chen - , Tsinghua University, Frontier Science Center for Quantum Information (Author)
  • Kai Liu - , Renmin University of China (Author)
  • Tian Long Xia - , Renmin University of China (Author)
  • Shancai Wang - , Renmin University of China (Author)

Abstract

Monolayer transition metal dichalcogenides (TMDs) have a simple crystal structure, but they exhibit intricate physical phenomena that differ from their bulk counterparts. Recently, there has been significant interest in the electronic behavior of monolayer TMDs hosted in a natural van der Waals superlattice material, Ba6Nb11S28, consisting of alternating NbS2 monolayers and block layers. Here, we report the electronic structure study of Ba6Nb11S28 and Ba6Ta11S28. Using angle-resolved photoemission spectroscopy and density functional theory calculation, we show that the electronic structures of the superlattices are similar to those of monolayer TMDs. The two-dimensional characteristics indicate that the interlayer coupling of adjacent TMD layers is suppressed by the intercalation of the Ba3NbS5 or Ba3TaS5 block layer. A clear band splitting due to spin-orbital coupling is observed in Ba6Ta11S28, while no obvious splitting is found in Ba6Nb11S28. These observations are in qualitative agreement with the observation on monolayer films of NbS2 and TaS2. Based on our findings, these natural superlattices can serve as an effective model system for studying monolayer materials and their potential applications.

Details

Original languageEnglish
Article number155115
JournalPhysical Review B
Volume109
Issue number15
Publication statusPublished - 15 Apr 2024
Peer-reviewedYes