北京大学孙栋团队研究了基于多层石墨烯的维度增强中红外光涡旋检测。该项研究成果发表在2025年3月6日出版的《光：科学与应用》杂志上。

最近对光涡旋的直接光电流读出的概念性演示使光轨道角动量敏感焦平面阵列和轨道角动量检测的片上集成得以发展。然而，已知的轨道角动量敏感材料仅限于属于C_2v点群的两种拓扑Weyl半金属，即WTe₂和TaIrTe₄。两者在环境条件下都很脆弱，对大规模外延生长具有挑战性。

在这项工作中，研究组证明了多层石墨烯是互补的金属-氧化物-半导体兼容的，可以在晶片尺度上外延生长，适用于中红外区域的轨道角动量检测。使用具有设计的U形电极几何形状的多层石墨烯光电探测器，他们证明了轨道角动量的拓扑电荷可以通过轨道光阀效应直接检测到，多层石墨烯的轨道角动量识别能力比TaIrTe₄大一个数量级。

研究结果发现，由于维度和散射率的降低，多层石墨烯的检测能力由增强的轨道光阀效应响应实现。该工作为提高轨道角动量识别能力开辟了一条新的技术路线，并可立即应用于环境稳定的中红外直接轨道角动量光电探测设备的大规模集成。

附：英文原文

Title: Dimensionality-enhanced mid-infrared light vortex detection based on multilayer graphene

Author: Yang, Dehong, Lai, Jiawei, Fan, Zipu, Wang, Shiyu, Chang, Kainan, Meng, Lili, Cheng, Jinluo, Sun, Dong

Issue&Volume: 2025-03-06

Abstract: Recent conceptual demonstrations of direct photocurrent readout of light vortices have enabled the development of light orbital angular momentum-sensitive focal plane arrays and on-chip integration of orbital angular momentum detection. However, known orbital angular momentum-sensitive materials are limited to two topological Weyl Semimetals belonging to the C2v point group, namely, WTe2 and TaIrTe4. Both are fragile under ambient conditions and challenging for large-scale epitaxial growth. In this work, we demonstrate that multilayer graphene, which is complementary metal–oxide–semiconductor compatible and epitaxially growable at the wafer scale, is applicable for orbital angular momentum detection in the mid-infrared region. Using a multilayer graphene photodetector with a designed U-shaped electrode geometry, we demonstrate that the topological charge of orbital angular momentum can be detected directly through the orbital photogalvanic effect and that the orbital angular momentum recognition capability of multilayer graphene is an order of magnitude greater than that of TaIrTe4. We found that the detection capability of multilayer graphene is enabled by the enhanced orbital photogalvanic effect response due to the reduced dimensionality and scattering rate. Our work opens a new technical route to improve orbital angular momentum recognition capability and is immediately applicable for large-scale integration of ambient stable, mid-infrared direct orbital angular momentum photodetection devices.

DOI: 10.1038/s41377-024-01735-4

Source: https://www.nature.com/articles/s41377-024-01735-4