Electric field-induced second harmonic generation (EFISH) allows for electrical control of nonlinear light-matter interactions, crucial for integrated photonics. This study demonstrates that polar skyrmions in PbTiO3/SrTiO3 ferroelectric superlattices exhibit high EFISH performance, achieving a second-order nonlinear susceptibility of -54.2 pm V⁻¹ and a modulation depth of -664% V⁻¹. The response boasts a bandwidth exceeding 10 MHz, a wide operating temperature range (~400 K), and good fatigue resistance (>10¹⁰ cycles). Experiments and phase-field simulations link the polarization configuration and field-induced skyrmion transitions to the EFISH response, highlighting the potential of topological polar structures for photonic and optoelectronic applications.

Sixu Wang, Wei Li, Chenguang Deng, Zijian Hong, Han-Bin Gao, Xiaolong Li, Yueliang Gu, Qiang Zheng, Yongjun Wu, Paul G. Evans, Jing-Feng Li, Ce-Wen Nan, Qian Li