Bursting at the seams: Rippled monolayer bismuth on NbSe2

• Published in: Science advances Vol. 4; no. 4
• Main Authors: Fang, Alan, Adamo, Carolina, Jia, Shuang, Cava, Robert J., Wu, Shu-Chun, Felser, Claudia, Kapitulnik, Aharon
• Format: Journal Article
• Language: English
• Published: United States AAAS 13.04.2018
• Subjects: MATERIALS SCIENCE
• ISSN: 2375-2548; 2375-2548

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant close to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.