Wang Sixu, Li Wei, Deng Chenguang, Hong Zijian, Gao Han-Bin, Li Xiaolong, Gu Yueliang, Zheng Qiang, Wu Yongjun, Evans Paul G, Li Jing-Feng, Nan Ce-Wen, Li Qian
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China.
School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, China.
Nat Commun. 2024 Feb 14;15(1):1374. doi: 10.1038/s41467-024-45755-5.
Electric field-induced second harmonic generation allows electrically controlling nonlinear light-matter interactions crucial for emerging integrated photonics applications. Despite its wide presence in materials, the figures-of-merit of electric field-induced second harmonic generation are yet to be elevated to enable novel device functionalities. Here, we show that the polar skyrmions, a topological phase spontaneously formed in PbTiO/SrTiO ferroelectric superlattices, exhibit a high comprehensive electric field-induced second harmonic generation performance. The second-order nonlinear susceptibility and modulation depth, measured under non-resonant 800 nm excitation, reach ~54.2 pm V and ~664% V, respectively, and high response bandwidth (higher than 10 MHz), wide operating temperature range (up to ~400 K) and good fatigue resistance (>10 cycles) are also demonstrated. Through combined in-situ experiments and phase-field simulations, we establish the microscopic links between the exotic polarization configuration and field-induced transition paths of the skyrmions and their electric field-induced second harmonic generation response. Our study not only presents a highly competitive thin-film material ready for constructing on-chip devices, but opens up new avenues of utilizing topological polar structures in the fields of photonics and optoelectronics.
电场诱导二次谐波产生能够实现对非线性光与物质相互作用的电控制，这对于新兴的集成光子学应用至关重要。尽管其在材料中广泛存在，但电场诱导二次谐波产生的品质因数仍有待提高，以实现新型器件功能。在此，我们表明，极性斯格明子是在PbTiO₃/SrTiO₃铁电超晶格中自发形成的一种拓扑相，具有高综合电场诱导二次谐波产生性能。在非共振800nm激发下测量的二阶非线性极化率和调制深度分别达到约54.2pm/V和约664%/V，并且还展示了高响应带宽（高于10MHz）、宽工作温度范围（高达约400K）和良好的抗疲劳性（>10⁶ 次循环）。通过原位实验和相场模拟相结合，我们建立了斯格明子奇异极化构型与场诱导转变路径及其电场诱导二次谐波产生响应之间的微观联系。我们的研究不仅提出了一种极具竞争力的薄膜材料，可用于构建片上器件，而且为在光子学和光电子学领域利用拓扑极性结构开辟了新途径。
