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arXiv 1702.02679cond-mat.mtrl-scicond-mat.mes-hallphysics.comp-ph
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90°扭曲双层黑磷膜的门开关输运和光学各向异性

Gate Switchable Transport and Optical Anisotropy in 90° Twisted Bilayer Black Phosphorus

Ting Cao, Zhenglu Li, Diana Y. Qiu, Steven G. Louie

摘要:

各向异性描述了材料性质的方向依赖性,例如传输和光学响应。在传统的块体材料中,各向异性本质上与晶体结构相关,因此不能通过现代电子学中使用的选通技术进行调节。在这里,我们表明,在双层黑磷与层间扭转角为90°,其电子结构和光学跃迁的各向异性是可调的门控。使用第一性原理计算,我们预测,一个实验室可访问的栅极电压可以诱导一个空穴的有效质量是30倍沿笛卡尔轴比沿其他轴,和两个轴可以通过翻转栅极电压的符号交换。这种门控能带结构还导致可切换的光学线性二向色性,其中最低能量光学跃迁(吸收或发光)的偏振可通过门控来调谐。因此,各向异性是扭曲双层黑磷中的可调自由度。

英文摘要:

Anisotropy describes the directional dependence of a material's properties such as transport and optical response. In conventional bulk materials, anisotropy is intrinsically related to the crystal structure, and thus not tunable by the gating techniques used in modern electronics. Here we show that, in bilayer black phosphorus with an interlayer twist angle of 90°, the anisotropy of its electronic structure and optical transitions is tunable by gating. Using first-principles calculations, we predict that a laboratory-accessible gate voltage can induce a hole effective mass that is 30 times larger along one Cartesian axis than along the other axis, and the two axes can be exchanged by flipping the sign of the gate voltage. This gate-controllable band structure also leads to a switchable optical linear dichroism, where the polarization of the lowest-energy optical transitions (absorption or luminescence) is tunable by gating. Thus, anisotropy is a tunable degree of freedom in twisted bilayer black phosphorus.

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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