Different from introducing ferromagnetism in three-dimensional (3D) topological insulators, empowering nontrivial band topology with 2D ferromagnetic (2DFM) materials is another way to realize quantum anomalous Hall effect (QAHE). The recently discovered 2DFM insulators provide unprecedented opportunities for realizing such an intriguing phenomenon. Here, by using first-principles approaches, w...

When covered by gadolinium (Gd) atoms, silicene, a freestanding monolayer of Si atoms in honeycomb network, remains stable above the room temperature and becomes two-dimensional (2D) ferromagnetic semiconductor, despite antiferromagnetic ground state three-dimensional bulk ${\mathrm{GdSi}}_{2}$ crystal. In thin multilayers, even if magnetic moments are ordered parallel same Gd atomic planes, th...

Bing Huang, Hui-Xiong Deng, Hoonkyung Lee, Mina Yoon, Bobby G. Sumpter, Feng Liu, Sean C. Smith, and Su-Huai Wei National Renewable Energy Laboratory, Golden, Colorado 80401, USA Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6493, USA State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of S...

Mono-elemental two-dimensional (2D) crystals (graphene, silicene, germanene, stanene, and so on), termed 2D-Xenes, have been brought to the forefront of scientific research. The stability and electronic properties of 2D-Xenes are main challenges in developing practical devices. Therefore, in this review, we focus on 2D free-standing group-IV graphene analogs (graphene quantum dots, silicane, an...

We report on the initial stage of growing of silicon nanostructures on Pb-induced √ 3 × √ 3 and √ 3 × √ 7 reconstructed Si(111) surfaces. The deposition of 0.75 monolayer of Si at a temperature of around 200 K results in Si nanoribbons a few-nanometers in length running in three equivalent high symmetry directions of Si(111) surface, as revealed by low temperature scanning tunneling microscopy ...

Free standing silicene nanosheets remain elusive presumably due to the instability associated with sp(2) hybridized silicon atoms. Here we show that silicon prefers nanosheets based on the non-classical Si5 unit with a [1.1.1]-propellane motif that has two inverted tetrahedral atoms bridged by three tetrahedral atoms. DFT calculations show that nanosheets constructed exclusively from propellane...