Magnetic Assembly of Co Atoms on 2D alpha-Sn Topological Insulator
Chia-Ju Chen1*, Shih-Tang Huang1, Yen-Hui Lin1, Ta-Yu Yeh1, Deng-Sung Lin1, Ye-Shun Lan1, Angus Huang1, Horng-Tay Jeng1, Pin-Jui Hsu1
1Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
* Presenter:Chia-Ju Chen,
A 2D topological insulator is a promising candidate for realizing the quantum spin Hall effect. Due to the time-reversal symmetry, the backscattering channel is forbidden on the robustness edge state gives rise to dissipationless electric conduction. Stanene is a promising material with various properties that have been reported with large quantum spin/anomalous Hall gaps (~0.3 eV) at room temperature and have been discovered superconductivity in a few-layer thickness. In this study, we deposit a small amount of Co atoms onto the submonolayer flat islands of α-Sn (stanene) on the Cu(111) by the low temperature growth. By utilizing scanning tunneling microscopy/spectroscopy techniques, the topographic images show Co atoms form the triangular trimers and dumbbell dimers on the top of the stanene islands. Besides, the differential conductance spectra taken on the Co atoms reveal a distinct peak at -0.3 eV, which has been theoretically indicated as an occupied minority d -like spin-polarized surface state. The self-assembled Co atoms may offer an interesting way to artificially build up local magnetic properties on top of the monolayer stanene down to the atomic scale.

Keywords: 2D Topological Insulator, Stanene, Self-assembled Co atoms