[7p-C11-1~21] 17.3 Layered materials

▲ [7p-C11-6] DFT study of a triangular lattice atomic layer of group IV elements (Ge, Sn, Pb) on SiC(0001)

〇Anton Visikovskiy¹, Shingo Hayashi¹, Takashi Kajiwara¹, Fumio Komori², Satoru Tanaka¹ (1.Kyushu Univ., 2.Univ. of Tokyo)

Keywords:2D atomic layers, Rashba effect, triangular lattice

Two-dimensional (2D) materials are one of the attention centers of material science due to their fascinating physical properties and potential device application. Most of the efforts are applied towards materials with honeycomb lattice such as graphene, silicene, germanene and similar. This is because of interesting physics of Dirac fermions. It was shown, however, that Dirac-like electron dispersion is possible in non-honeycomb lattices, however the studies of non-honeycomb lattice 2D materials are rather rare up to date. One of such possible atomic lattices is a triangular one. Here we present our ab initio calculations and experimental results showing that such triangular atomic lattices of Ge, Sn and Pb could be stable on SiC(0001), and especially at graphene/SiC(0001) interface. Non-trivial bonding configuration in this 2D layers results in formation of perfect 2D metal. It also exhibits Dirac-cone-like electron dispersion features. Owing to large spin-orbit interaction (SOI), these layers show both Rashba- and non-Rashba-type of spin-polarization of electron bands at high symmetry points in the Brillouin zone simultaneously which has not been observed before and represents an interesting case both for science and possible application in spintronic device application.