Interfacial Coupling Reshapes Nonlinear Polarization in a Spin-Defect van der Waals Heterostructure
Abstract
Van der Waals heterostructures offer a direct route to couple an optically active layer to a two-dimensional spin sensor, yet their coherent nonlinear response at interfaces remains poorly resolved. Here, we use polarization-resolved second harmonic-generation imaging to resolve four distinct regions of a hexagonal boron nitride (hBN) -based heterostructure, native hBN, neutron-irradiated hBN containing negatively charged boron vacancies (VB-), PbI2 and their complete overlap. The detected intensity scales quadratically with incident power, consistent with a dominant second-order optical process. Polarization scans show that adding PbI2 transforms the distorted VB- SHG anisotropy into a predominantly fourfold response with a sixfold stronger SHG than native hBN alone. This non-additive nonlinear response occurs in the same layer architecture also shown to enhance defect photoluminescence, linking spin-defect sensitization to an interface-modified effective second-order susceptibility.
Related
- Amplification of valley polarization in an hBN-separated MoSe2-WSe2 heterostructure
- 1D Interface-Induced Real-Space Berry Curvature Gradient Encoded in SpinValley-Coupled Nonlinear Photocurrent in Lateral Heterostructure
- Surfactant-Induced Interfacial Anisotropy Governs Polarization-Selective Whispering Gallery Mode Excitation in Dye-Doped Trapped Microdroplets
- Zero-Point Renormalization Reshapes the Shift Current: The Role of Electron-Phonon Coupling
- Sparse Contextual Coupling Reshapes Diffusion Geometry in Multilayer Hypergraphs
BibTeX
@misc{dalifoski2026interfacial,
title = {{Interfacial Coupling Reshapes Nonlinear Polarization in a Spin-Defect van der Waals Heterostructure}},
author = {Lena Dalifoski and Eveline Mayner and Poonam Singh},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.15189},
eprint = {2610.15189},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.15189},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Interfacial Coupling Reshapes Nonlinear Polarization in a Spin-Defect van der Waals Heterostructure
AU - Lena Dalifoski
AU - Eveline Mayner
AU - Poonam Singh
PY - 2026
DA - 2026/10/10
PB - arXiv
DO - 10.48550/arxiv.2610.15189
UR - https://arxiv.org/abs/2610.15189
AB - Van der Waals heterostructures offer a direct route to couple an optically active layer to a two-dimensional spin sensor, yet their coherent nonlinear response at interfaces remains poorly resolved. Here, we use polarization-resolved second harmonic-generation imaging to resolve four distinct regions of a hexagonal boron nitride (hBN) -based heterostructure, native hBN, neutron-irradiated hBN containing negatively charged boron vacancies (VB-), PbI2 and their complete overlap. The detected intensity scales quadratically with incident power, consistent with a dominant second-order optical process. Polarization scans show that adding PbI2 transforms the distorted VB- SHG anisotropy into a predominantly fourfold response with a sixfold stronger SHG than native hBN alone. This non-additive nonlinear response occurs in the same layer architecture also shown to enhance defect photoluminescence, linking spin-defect sensitization to an interface-modified effective second-order susceptibility.
ER -