Boosting classical and quantum nonlinear processes in ultrathin van der Waals materials

Xiaodan Lyu, Leevi Kallioniemi, Hongbing Cai, Liheng An, Ruihuan Duan, Shuin Jian Wu, Qinghai Tan, Chusheng Zhang, Ruihua He, Yansong Miao, Zheng Liu, Alexander Ling, Jesus Zúñiga-Perez*, Weibo Gao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Understanding and controlling nonlinear processes is crucial for engineering light-matter interaction and generating non-classical light. A significant challenge in ultra-thin nonlinear materials is the marked diminution of the nonlinear conversion efficiency due to the reduced light-matter interaction length and, in many cases, the centrosymmetric crystalline structures. Here we relax these limitations and report a giant boost of classical and quantum nonlinear processes in ultrathin van der Waals materials. Specifically, with a metal-nonlinear material heterostructure we enhance classical second-harmonic generation in h-BN flakes by two orders of magnitude. Moreover, we have engineered a metal-SiO2-nonlinear material heterostructure resulting in a remarkable two orders of magnitude augmentation of the quantum spontaneous parametric down-conversion (SPDC) in NbOCl2 flakes. Notably, we demonstrate SPDC in a 16 nm-thick NbOCl2 flake integrated into the proposed structure. These findings simplify on-chip quantum state engineering and accelerate the use of van der Waals materials in nonlinear optoelectronics.

Original languageEnglish
Article number4987
JournalNature Communications
Volume16
Issue number1
DOIs
Publication statusPublished - Dec 2025
Externally publishedYes

Bibliographical note

Publisher Copyright:
© The Author(s) 2025.

ASJC Scopus Subject Areas

  • General Chemistry
  • General Biochemistry,Genetics and Molecular Biology
  • General Physics and Astronomy

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