标题:Prediction of large-gap quantum spin hall insulator and Rashba-Dresselhaus effect in two-dimensional g-TIA (A = N, P, As, and Sb) monolayer films
作者:Xinru Li[1];Ying Dai[1];Yandong Ma[1];Wei Wei[1];Lin Yu[1];Baibiao Huang[2]
作者机构:[Xinru Li;Ying Dai;Yandong Ma;Wei Wei;Lin Yu]School of Physics, Shandong University, Jinan 250100, China.;[Baibiao Huang]State Key Laboratory of Cryst 更多
来源:纳米研究:英文版
出版年:2015
期:09
关键词:two-dimensionalmonolayers,topological;insulators,quantum;spin;HALL;effect,Rashba-Dresselhaus;effect,density;functional;theories;
摘要:A new family of two-dimensional (2D) topological insulators (TIs) comprising g-TIA (A = N, P, As, and Sb) monolayers constructed by T1 and group-V elements is predicted by first-principles calculations and molecular-dynamics (MD) simulations. The geometric stability, band inversion, nontrivial edge states, and electric polarity are investigated to predict the large-gap quantum spin Hall insulator and Rashba-Dresselhaus effects. The MD results reveal that the g-T1A monolayers remain stable even at room temperature. The g-T1A (A = As, Sb) monolayers become TIs under the influence of strong spin-orbit couplings with large bulk bandgaps of 131 and 268 meV, respectively. A single band inversion is observed in each g-T1A (A = As, Sb) monolayer, indicating a nontrivial topological nature. Furthermore, the topological edge states are described by introducing a sufficiently wide zigzag-nanoribbon. A Dirac point in the middle of the bulk gap connects the valence- and conduction-band edges. The Fermi velocity near the Dirac point with a linear band dispersion is -0.51 × 106 m/s, which is comparable to that of many other 2D nanomaterials. More importantly, owing to the broken inversion symmetry normal to the plane of the g-T1A films, a promising Rashba-Dresselhaus effect with the parameter up to 0.85 eV-A is observed in the g-T1A (A = As, Sb) monolayers. Our findings regarding 2D topological g-T1A monolayers with room-temperature bandgaps, intriguing topological edge states, and a promising Rashba-Dresselhaus effect are of fundamental value and suggest potential applications in nanoelectronic devices.
资源类型:期刊论文
原文链接:http://lib.cqvip.com/qk/71233X/201509/666903183.html
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