Developing graphene-based nanoelectronics hinges on opening a band gap in the electronic structure of graphene, which is commonly achieved by breaking the inversion symmetry of the graphene lattice via an electric field (gate bias) or asymmetric doping of graphene layers. Here we introduce a new design strategy that places a bilayer graphene sheet sandwiched between two cladding layers of materials that possess strong spin-orbit coupling (e.g., Bi2Te3). Our ab initio and tight-binding calculations show that proximity enhanced spin-orbit coupling effect opens a large (44 meV) band gap in bilayer graphene without breaking its lattice symmetry, and the band gap can be effectively tuned by interlayer stacking pattern and significantly enhanced by interlayer compression. The feasibility of this quantum-well structure is demonstrated by recent experimental realization of high-quality heterojunctions between graphene and Bi2Te3, and this design also conforms to existing fabrication techniques in the semiconductor industry. The proposed quantum-well structure is expected to be especially robust since it does not require an external power supply to open and maintain a band gap, and the cladding layers provide protection against environmental degradation of the graphene layer in its device applications.
Guidelines for band gap opening in graphene superlattices with periodic π-vacancy distribution
Technische Universität Dresden（德累斯顿工业大学）；Center for Advanced System Understanding CASUS, Helmholtz-Zentrum Dresden-Rossendorf e. V.（亥姆霍兹德累斯顿-罗斯多夫中心高级系统理解中心）；Yonsei University（延世大学）
Bulk transport properties of Bismuth selenide thin films approaching the two-dimensional limit
我们研究了拓扑绝缘体Bi 2 Se 3薄膜的输运性质，重点是了解作为厚度的函数的行为。我们表明，厚度有很强的影响，各方面的运输作为二维极限的接近。体电阻率和霍尔迁移率显示不成比例的大的变化低于6五重层，我们直接相关的几层Bi2Se3的体带隙的增加，这种效果是伴随着表面间隙开口。在超薄Bi2Se3中的温度依赖性电阻率测量中从金属到绝缘行为的交叉趋势也与体带隙的增加以及膜-衬底界面处的增强的无序一致。我们的工作突出了少层Bi2Se3的性质是可调的，这可能是有吸引力的各种器件应用领域，如光电子学，纳米电子学和自旋电子学。
Engineering Altermagnetism via Layer Shifts and Spin Order in Bilayer MnPS$_3$
Universidad de Antofagasta（安托法加斯塔大学）；Technische Universität Dresden（德累斯顿工业大学）；Universidad Técnica Federico Santa María（费德里科·圣塔玛丽亚技术大学）；Universidad de Chile（智利大学）；Dresden University of Technology, Institute for Solid State and Materials Physics（德累斯顿工业大学固体与材料物理研究所）
