Alkali-metal induced electronic structure evolution in Sn4Sb3 studied by angle-resolved photoemission spectroscopy. (March 2022)

• Record Type: Journal Article
• Authors: Wen, Wei; Duan, Xu; Liu, Bin; Hong, Caiyun; Song, Zhen; Lin, Bing; Ran, Pengxu; Liu, Shi; Ren, Zhi; He, Rui-Hua
• Is Part Of: Journal of physics and chemistry of solids. Volume 162(2022)
• Publication Date: 2022-03
• Subjects: Angle-resolved photoemission spectroscopy -- Topological semimetal -- Alkali metal dosing -- Intercalation -- Dirac cone; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2021.110526
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: We report on an angle-resolved photoemission spectroscopy study of the effect of in-situ cesium (Cs) dosing on the surface electronic structure of Sn4 Sb3, a newly emerging candidate of topological semimetallic superconductor. As the chemical potential of the system increases upon Cs dosing, we observed an electronic structure evolution that features an increasing sharpness of band features as well as a momentum- and band-dependent energy shift of the bands at low binding energies. These observations go beyond a simple rigid band shift model and are manifestations of quantum confinement of electronic states near the surface due to Cs decoration. By studying the evolution of Cs 5 p core level as functions of Cs dosage and photoelectron emission angle, we found Cs atoms deposit on the sample surface at low dosages and tend to intercalate underneath the surface at high dosages. This process is accompanied by a gradual suppression of a surface band splitting, an observation that can be captured by simplified first-principles calculations in both cases with the deposition/intercalation occurring on top of/underneath the first Sn–Sb bilayer. Our finding highlights an intriguing possibility of an unexpected dimensionality reduction in Sn4 Sb3 caused by Cs intercalation at interstitial sites that promises its novel surface properties different from the bulk. Highlights: First ARPES study of Cs-induced electronic structure evolution in Sn4 Sb3 . Quantum confinement of electronic states due to Cs decoration. Evidence for interstitial intercalation. Electronic dimensionality reduction in Sn4 Sb3 caused by Cs intercalation.