Surface alloy engineering in 2D trigonal lattice: giant Rashba spin splitting and two large topological gaps

5 years ago

Surface alloy engineering in 2D trigonal lattice: giant Rashba spin splitting and two large topological gaps

We demonstrate that sp 2 based trigonal lattice can exhibit giant Rashba splitting and two large topological gaps simultaneously. First, an effective tight binding model is developed to describe the Rashba spin–orbit coupling (SOC) on a real surface and give a topological phase diagram based on two independent SOC parameters. Second, based on density functional theory calculations, it is proposed that Au/Si(111)- ##IMG## [http://ej.iop.org/images/1367-2630/20/2/023041/njpaaab98ieqn1.gif] {$\sqrt{3}\times \sqrt{3}$} surface with 1/3 monolayer Bi coverage is a good material candidate to realize both giant Rashba splitting and two large topological gaps. These results would inspire great research interests for searching two-dimensional topological insulator and manipulating Rashba spin splitting through surface alloy engineering.

Publisher URL: http://iopscience.iop.org/1367-2630/20/2/023041

DOI: 10.1088/1367-2630/aaab98