Li Dawei, Huang Xi, Xiao Zhiyong, Chen Hanying, Zhang Le, Hao Yifei, Song Jingfeng, Shao Ding-Fu, Tsymbal Evgeny Y, Lu Yongfeng, Hong Xia
Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, 68588-0299, USA.
Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588-0511, USA.
Nat Commun. 2020 Mar 17;11(1):1422. doi: 10.1038/s41467-020-15191-2.
Complex oxide heterointerfaces and van der Waals heterostructures present two versatile but intrinsically different platforms for exploring emergent quantum phenomena and designing new functionalities. The rich opportunity offered by the synergy between these two classes of materials, however, is yet to be charted. Here, we report an unconventional nonlinear optical filtering effect resulting from the interfacial polar alignment between monolayer MoS and a neighboring ferroelectric oxide thin film. The second harmonic generation response at the heterointerface is either substantially enhanced or almost entirely quenched by an underlying ferroelectric domain wall depending on its chirality, and can be further tailored by the polar domains. Unlike the extensively studied coupling mechanisms driven by charge, spin, and lattice, the interfacial tailoring effect is solely mediated by the polar symmetry, as well explained via our density functional theory calculations, pointing to a new material strategy for the functional design of nanoscale reconfigurable optical applications.
复杂氧化物异质界面和范德华异质结构为探索新兴量子现象和设计新功能提供了两个通用但本质上不同的平台。然而，这两类材料之间协同作用所带来的丰富机遇尚未得到充分探索。在此，我们报道了一种非常规的非线性光学滤波效应，该效应源于单层MoS与相邻铁电氧化物薄膜之间的界面极性排列。根据其手性，异质界面处的二次谐波产生响应会被下层铁电畴壁显著增强或几乎完全淬灭，并且可以通过极性畴进一步调整。与广泛研究的由电荷、自旋和晶格驱动的耦合机制不同，界面剪裁效应仅由极性对称性介导，正如我们的密度泛函理论计算所很好解释的那样，这为纳米级可重构光学应用的功能设计指明了一种新的材料策略。
