Extrinsic Magnetic Doping of Two-Dimensional Topological Insulator (Stanene) with Magnetic Atoms

Nitin Kumar^1*, Chia-Ju Chen¹, Yen-Hui Lin¹, Ye-Shun Lan¹, Horng-Tay Jeng^1,2, Pin-Jui Hsu¹

¹Department of Physics, National Tsing Hua University, East District, Hsinchu, Taiwan
²Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:Nitin Kumar, email:itsnitin95@gmail.com

Quantum Hall insulators (QHI) have dissipationless conducting channels but their use is limited to the research laboratories because of the demand for a strong external magnetic field and low temperature. But quantum anomalous Hall insulators (QAHI) or magnetic topological insulators overcame these limitations and proved to be the future of low power consumption electronics. Inducing magnetism in a quantum spin Hall insulator (QSHI) is an appropriate way to produce QAHI. An unusual ultra-flat 2D stanene was grown on Cu (111) substrate and doped with magnetic Co atoms. System was studied with scanning tunneling microscopy/spectroscopy at low temperature in conjunction with theoretical studies. Co atoms formed single, double, and triple atomic structures by substituting Sn atoms in 2D stanene. Structure models for Co atoms were proposed based on the atomically resolved topographic images and verified with first-principle calculations. The magnetic moments of the Co atoms were calculated by density function theory (DFT).

Keywords: Topological Insulator, Quantum Anomalous Hall Effect, Scanning Tunneling Microscopy, Spin-Orbital Coupling