Programmable Light-Matter Interactions in Atomically Tailored Quantum Materials

Artificial atomic and mesoscale structures in two-dimensional materials provide a powerful platform to engineer light–matter interactions, explore emergent quantum optical phenomena, and access application-specific regimes. In this talk, I will discuss our recent advancements in controlling quantum light and excitons in atomically tailored van der Waals materials, spanning defect-engineered quantum emitters in wide-bandgap materials and excitonic confinement in mixed-phase layered semiconductors.

In the first part, I will present recent advances in defect-based quantum emitters in hexagonal boron nitride (hBN), including our observation of elementary excitations associated with single-photon emission [1] and evidence of delocalized donor–acceptor-like recombination processes within hybrid defect complexes [2]. These results reveal a new microscopic picture of quantum emission in hBN and establish a pathway toward electrically programmable quantum light sources and novel realizations of the spin-boson coupling regime in solid-state systems. 

In the second part, I will discuss the emergence of new optical states beyond standard excitons in transition metal dichalcogenide (TMD) monolayers, including dark excitonic states and interface excitons at phase boundaries. Our methods to directly visualize and manipulate dark exciton states enable the observation of interaction-driven long-range transport [3,4] and establish dark excitons as sensitive probes of local strain and many-body dynamics in atomically thin materials [5,6]. I will then introduce a new platform for exciton confinement based on mixed-phase nanostructures [7]. By spatially patterning semiconducting and metallic phases within atomically thin crystals, we realize highly confined one-dimensional excitonic channels with customizable geometries, enabling the investigation of quantum-confined excitons, nonlinear transport, and coherent light–matter states in reduced dimensions. Together, these results establish synthetic two-dimensional materials as a versatile platform to explore, design, and control quantum optical states for future photonic and quantum technologies.

References
[1] Pelliciari, J. et al., Nature Materials 23, 1230-1236 (2024)
[2] Mejia, A.E. et al., J. Phys. Chem. C 129, 2044 (2025)
[3] Chand, S.B. et al., Nature Communications 14, 3712 (2023)
[4] Quan, J. et al., Nature Photonics 20, 49–54 (2026)
[5] Chand, S.B., et al., Nano Letters 22, 3087-3094 (2022)
[6] Chand, S.B. et al., Advanced Optical Materials 14, no. 13 (2026): e03833
[7] Woods, J. M. et al., ACS Photonics 11, 3784-3793 (2024)