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arXiv · 2411.04961

Nonlinear Broadband THz Generation from NV Centers in Bulk Diamond Crystals

Hani Barhum·Cormac McDonnell·Tamara Amro·Ilya Simanovsky·Pavel Ginzburg·Nir Bar-Gill·Aharon Blank·Mohammad Attrash
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Abstract

Diamond single crystals are promising nonlinear THz sources due to their high damage threshold, transparency, and small dispersion linear dispersion over THz-NIR which enables relaxing the need for additional phase-matching engineering . However, the centrosymmetry of a diamond's lattice prohibits even-order nonlinear effects, including second harmonic generation and optical rectification. We demonstrate broadband THz emission via optical rectification in an NV-doped diamond, where NV centers break inversion symmetry and induce a nonlinear susceptibility in the lattice. THz time-domain spectroscopy reveals single-cycle emission spanning over 4 THz bandwidth, enabled by a high NV density (~200 ppm) and lattice strain. Density functional theory (DFT) confirms the emergence of finite second-order nonlinear susceptibility, directly linking symmetry breaking to THz generation. The wide bandgap and defect-induced strain support efficient THz emission without crystal damage, establishing NV-diamond as a robust platform for high-field ultrabroadband THz generation.

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Hani Barhum, Cormac McDonnell, Tamara Amro, Ilya Simanovsky, Pavel Ginzburg, Nir Bar-Gill, Aharon Blank, Mohammad Attrash. 2025-05-04. Nonlinear Broadband THz Generation from NV Centers in Bulk Diamond Crystals. https://arxiv.org/abs/2411.04961

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