Nonlinear Nanophotonics

Nonlinear optics is a fundamental resource for quantum technologies, enabling essential operations like the generation of entangled photon pairs. While traditional bulk crystals require strict phase-matching that tightly constrains device design, scaling materials down to the ultimate thickness limit unlocks a highly flexible, phase-matching-free regime. This freedom allows us to engineer quantum sources without the rigid geometric and dispersive limitations of conventional optics.

Our group investigates ultra-thin media and 2D materials to develop scalable nanophotonic quantum hardware. Because identifying the right physical platform is critical, we utilize classical nonlinear optical measurements to rapidly characterize and discover new materials that exhibit exceptionally strong nonlinearities.

Harnessing these advanced materials, we have demonstrated that we can generate novel types of entangled states directly within ultra-thin platforms. Operating in a phase-matching-free regime not only preserves the inherent quality of the emitted photons by minimizing internal scattering and dispersion, but it also opens the door to entirely new quantum state engineering capabilities.

Moving forward, we aim to exploit the unique flexibility of these nanophotonic platforms to push the boundaries of photonic quantum information. Our ongoing research focuses on generating complex quantum states natively using ultra-thin materials materials, with specific work  targeting high-dimensional entanglement,  N00N states, and ultra-broadband frequency entanglement.

Plasmon-Enhanced Second-Harmonic Generation in Atomically This Crystalline Silver Nanostructures
S. Abdullah et al., Advanced Materials e72517 (2026).

Few-atom-thick silver films for enhanced nanoscale nonlinear optics
P. K. Jenke et al., Nature Communications 17 (2026).

Scaling native entanglement generation in layered semiconductors with quasi-phase matching.
B. Braun et al., arXiv:2606.14553 (2026).

2D Materials for Photonics Quantum Information Processing, (in Roadmap for Photonics with 2D Materials)
L. A. Rozema, P. K. Jenke, J. Bajo, B. Braun, P. Walther, ACS Photonics (2025).

Quasi-phase-matched up- and down-conversion in periodically poled layered semiconductors
C. Trovatello et al., Nature Photonics 19, 291–299 (2025).

Giant enhancement of third-harmonic generation in graphene–metal heterostructures
I. Alonso Calafell et al., Nature Nanotechnology 16, 318–324 (2021).