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arXiv 1502.01805cond-mat.mtrl-sci
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利用应变控制双层磷分子中量子自旋霍尔态

Controlling quantum spin Hall state via strain in various stacking bilayer phosphorene

Tian Zhang, Jia-He Lin, Yan-Mei Yu, Xiang-Rong Chen, Wu-Ming Liu

摘要:

量子自旋霍尔(QSH)态物质具有一个电荷激发带隙和一对无带隙的自旋过滤边态,可以支持无背散射输运。双层磷烯具有大的可调带隙和高的载流子迁移率,在纳米电子学和光学领域有着广泛的应用前景。在这里,我们证明了应变诱导的电子拓扑相变从正常的QSH状态在双层磷伴随着带反转,改变$\mathbbm{Z}_{2}$从0到1,这是高度依赖于层间堆叠。当底层相对于顶层沿轴向移动1/2晶胞时,拓扑带隙达到92.5meV,这足以在室温下实现QSH效应。它的光吸收光谱变宽,甚至延伸到远红外区域,导致更宽的亮度范围,这在光学器件中是非常理想的。

英文摘要:

Quantum spin Hall (QSH) state of matter has a charge excitation bulk bandgap and a pair of gapless spin-filtered edge-states, which can support backscattering-free transport. Bilayer phosphorene possesses a large tunable bandgap and high carrier mobilities, and therefore has the widely potential applications in nanoelectronics and optics. Here, we demonstrate an strain-induced electronic topological phase transition from a normal to QSH state in bilayer phosphorene accompanying by a band inversion that changes $\mathbbm{Z}_{2}$ from 0 to 1, which is highly dependent on the interlayer stacking. When the bottom layer is shifted by 1/2 unit cell along axial direction with respect to the top layer, the topological bandgap reaches up to 92.5 meV, which is sufficiently large to realize the QSH effect at room temperature. Its optical absorption spectrum becomes broadened, and even extends to the far-infra-red region leading to a wider range of brightness, which is highly desirable in optic devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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