Cheng-Wei Qiu

@article{ISI:001376827800011,
title = {Polarization entanglement enabled by orthogonally stacked van der Waals NbOCl_{2} crystals},
author = {Qiangbing Guo and Yun-Kun Wu and Di Zhang and Qiuhong Zhang and Guang-Can Guo and Andrea Alu and Xi-Feng Ren and Cheng-Wei Qiu},
doi = {10.1038/s41467-024-54876-w},
times_cited = {0},
year = {2024},
date = {2024-12-02},
journal = {NATURE COMMUNICATIONS},
volume = {15},
number = {1},
publisher = {NATURE PORTFOLIO},
address = {HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY},
abstract = {Polarization entanglement holds significant importance for photonic quantum technologies. Recently emerging subwavelength nonlinear quantum light sources, e.g., GaP and LiNbO3 thin films, benefiting from the relaxed phase-matching constraints and volume confinement, have shown intriguing properties, such as high-dimensional hyperentanglement and robust entanglement anti-degradation. Van der Waals (vdW) NbOCl2 crystal, with strong optical nonlinearities, has emerged as a potential candidate for ultrathin quantum light sources. However, polarization entanglement is inaccessible in the NbOCl2 crystal due to its unfavorable nonlinear susceptibility tensor. Here, by leveraging the twist-stacking degree of freedom inherently in vdW systems, we showcase the preparation of polarization entanglement and quantum Bell states.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:001288597300001,
title = {Colossal in-plane optical anisotropy in a two-dimensional van der Waals crystal},
author = {Qiangbing Guo and Qiuhong Zhang and Tan Zhang and Jun Zhou and Shumin Xiao and Shijie Wang and Yuan Ping Feng and Cheng-Wei Qiu},
doi = {10.1038/s41566-024-01501-3},
times_cited = {5},
issn = {1749-4885},
year = {2024},
date = {2024-08-08},
journal = {NATURE PHOTONICS},
volume = {18},
number = {11},
publisher = {NATURE PORTFOLIO},
address = {HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY},
abstract = {Polarization, a fundamental property of light, has been widely exploited from quantum physics to high-dimensional optics. Materials with intrinsic optical anisotropy, such as dichroism and birefringence, are central to light polarization control, including the development of polarizers, waveplates, mirrors and phase-matching elements. Therefore, materials with strong optical anisotropy have been long-sought. Recently, two-dimensional van der Waals crystals show high optical anisotropy but are mostly restricted to the out-of-plane direction, which is challenging to access in optical engineering. Here we report a two-dimensional van der Waals material, NbOCl2, that exhibits sharp electronic and structural contrast between its in-plane orthogonal axes. Colossal in-plane optical anisotropy-linear dichroism (up to 99% in ultraviolet) and birefringence (0.26-0.46 within a wide visible-near-infrared transparency window)-is experimentally demonstrated. Our findings provide a powerful and easy-to-access recipe for ultracompact integrated polarization industries.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}