The electronic structure of Stanene on Cu (111) with angle-resolved photoemission spectroscopy
Shu-Hua Kuo1*, Jing-Yue Huang2, Shih-Wei Chiu1, Pei-Yu Chuang1, Horng-Tay Jeng2,3,4, Ping-Jui Hsu2, Cheng-Maw Cheng1,5,6
1Condensed Matter Physics Group, 1National Synchrotron Radiation Research Center, Hsinchu, Taiwan
2Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
3Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
4Institute of Physics, Academia Sinica, Taipei, Taiwan
5Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
6Taiwan Consortium of Emergent Crystalline Materials, Ministry of Science and Technology, Taipei, Taiwan
* Presenter:Shu-Hua Kuo,
Two-dimensional topological insulators (2D-TIs), have been attracting intense attentions during the past ten year in research areas of condensed matter physics owing to their electronic structures associated to a nontrivial band topology and topologically protected edge states. Tin (Sn), a common group IV element, has attracted much attention nowadays, not only for its large spin-orbit coupling (SOC), but also for integration compatible with semiconductor industry. Stanene, one of 2-D group-IV materials, has strong SOC and a large quantum spin Hall (QSH) and quantum anomalous Hall (QAH) gaps (~0.3 eV), which is benefit for room temperature nanoelectronic and optoelectronic applications. Here in, we had successfully growth 𝛼- and β-stanene on Cu (111) substrate by the molecular beam epitaxy (MBE) method. In 𝛼-stanene/Cu (111), a significant QSH and QAH band gap ~ 0.3 eV extracted from the band mapping result shows the consistency of previous study. Moreover, well-ordered β-stanene could be prepared on Cu(111) substrate and confirmed by the low energy electron diffraction (LEED). A novel Dirac state near the zone boundary was observed in the band mapping result, suggesting that β-stanene could be Dirac semimetal or nodal-line Dirac semimetal. In this work, a detail discussion of the band structure of 𝛼- and β-stanene will be presented. The deeper understanding of electronic structure of stanene would be significant in realizing the origin of higher temperature QSH effect.

Keywords: 2D material, MBE, ARPES, band structure, stanene