论文标题
非中心对称二维材料的等离子量子非线性霍尔效应
Plasmonic quantum nonlinear Hall effect in noncentrosymmetric 2D materials
论文作者
论文摘要
我们根据电子流体力学理论研究了量子几何效应和表面等离子体之间的相互作用。首先，我们证明量子非线性大厅效应可以通过利用等离子谐振和光栅门的近场效应在非常广泛的频率中显着增强。在谐振条件下，增强变成没有纳米结构的情况大的几个数量级，而高谐波等离子的峰值则广泛膨胀并在非谐振条件下出现，从而导致了较广泛的光谱。此外，我们阐明了由浆果曲率偶极子引起的光电流与光吸收之间的普遍关系，这对于长波长光电探测器的计算材料设计至关重要。接下来，我们将讨论一种新型的几何光电流机制，该机制源自振荡磁场引起的异常力，并通过动量空间中Bloch电子的轨道磁矩的偶极矩描述。我们的理论与2D量子材料有关，例如分层的WTE $ {} _ 2 $和扭曲的双层石墨烯，从而提供了一种有希望的途径，通向一种新型的高度敏感的宽带Terahertz光电探测器。
We investigate an interplay between quantum geometrical effects and surface plasmons through surface plasmonic structures, based on an electron hydrodynamic theory. First we demonstrate that the quantum nonlinear Hall effect can be dramatically enhanced over a very broad range of frequency by utilizing plasmonic resonances and near-field effects of grating gates. Under the resonant condition, the enhancement becomes several orders of magnitude larger than the case without the nanostructures, while the peaks of high-harmonic plasmons expand broadly and emerge under the off-resonant condition, leading to a remarkably broad spectrum. Furthermore, we clarify a universal relation between the photocurrent induced by the Berry curvature dipole and the optical absorption, which is essential for computational material design of long-wavelength photodetectors. Next we discuss a novel mechanism of geometrical photocurrent, which originates from an anomalous force induced by oscillating magnetic fields and is described by the dipole moment of orbital magnetic moments of Bloch electrons in the momentum space. Our theory is relevant to 2D quantum materials such as layered WTe${}_2$ and twisted bilayer graphene, thereby providing a promising route toward a novel type of highly sensitive, broadband terahertz photodetectors.
