Boosting classical and quantum nonlinear processes in ultrathin van der Waals materials
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.
Cite
@article{arxiv.2503.23075,
title = {Boosting classical and quantum nonlinear processes in ultrathin van der Waals materials},
author = {Xiaodan Lyu and Leevi Kallioniemi and Hongbing Cai and Liheng An and Ruihuan Duan and Shuin Jian Wu and Qinghai Tan and Chusheng Zhang and Ruihua He and Yansong Miao and Zheng Liu and Alexander Ling and Jesus Zúñiga Perez and Weibo Gao},
journal= {arXiv preprint arXiv:2503.23075},
year = {2025}
}