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arXiv · 2411.09421

A 2D van der Waals Material for Terahertz Emission with Giant Optical Rectification

Taketo Handa·Chun-Ying Huang·Yiliu Li·Nicholas Olsen·Daniel G. Chica·David D. Xu·Felix Sturm·James W. McIver·Xavier Roy·Xiaoyang Zhu
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Abstract

Exfoliation and stacking of two-dimensional (2D) van der Waals (vdW) crystals have created unprecedented opportunities in the discovery of quantum phases. A major obstacle to the advancement of this field is the limited spectroscopic access due to a mismatch in sample sizes (1 - 10 micrometer) and wavelengths (0.1 - 1 millimeter) of electromagnetic radiation relevant to their low-energy excitations. Here, we introduce a new member of the 2D vdW material family: a terahertz (THz) emitter. We show intense and broadband THz generation from the vdW ferroelectric semiconductor NbOI2 with optical rectification efficiency over one-order-of-magnitude higher than that of the current standard THz emitter, ZnTe. The NbOI2 THz emitter can be easily integrated into vdW heterostructures for on-chip near-field THz spectroscopy of a target vdW material/device. Our approach provides a general spectroscopic tool for the rapidly expanding field of 2D vdW materials and quantum matter.

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Taketo Handa, Chun-Ying Huang, Yiliu Li, Nicholas Olsen, Daniel G. Chica, David D. Xu, Felix Sturm, James W. McIver, Xavier Roy, Xiaoyang Zhu. 2024-11-14. A 2D van der Waals Material for Terahertz Emission with Giant Optical Rectification. https://doi.org/10.1038/s41563-025-02201-1

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