Tunable Layer Circular Photogalvanic Effect in Twisted Bilayers.
Tunable Layer Circular Photogalvanic Effect in Twisted Bilayers.
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DOI：
10.1103/physrevlett.124.077401
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发表时间：
2019-11
影响因子：
8.6
通讯作者：
Yang Gao;Yinhan Zhang;Di Xiao
中科院分区：
文献类型：
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作者：
Yang Gao;Yinhan Zhang;Di Xiao
我们提出了准二维手性双分子层中圆形光电效应（LCPGE）的一般理论，这是指由圆偏振光诱导的偏振依赖的面外静态偶极矩的出现。我们将LCPGE的几何起源解释为分别由量子度量张量和Berry曲率加权的两种层间坐标移位。作为一个具体的例子，我们计算了扭曲双层石墨烯中的LCPGE，发现它表现出一个共振峰，其频率可以随着扭曲角度的变化而从可见光到红外调谐。因此，LCPGE为频率敏感的圆偏振光探测提供了一条有希望的途径，特别是在红外范围内。
We develop a general theory of the layer circular photogalvanic effect (LCPGE) in quasi-two-dimensional chiral bilayers, which refers to the appearance of a polarization-dependent, out-of-plane static dipole moment induced by circularly polarized light. We elucidate the geometric origin of the LCPGE as two types of interlayer coordinate shift weighted by the quantum metric tensor and the Berry curvature, respectively. As a concrete example, we calculate the LCPGE in twisted bilayer graphene, and find that it exhibits a resonance peak whose frequency can be tuned from visible to infrared as the twisting angle varies. The LCPGE thus provides a promising route toward frequency-sensitive, circularly polarized light detection, particularly in the infrared range.