近日，巴基斯坦工程与应用科学研究所的Muhammad Waseem与浙江师范大学的Muzamil Shah等人合作并取得一项新进展。经过不懈努力，他们实现了光子自旋霍尔效应的增益辅助控制。相关研究成果已于2024年9月9日在国际知名学术期刊《物理评论A》上发表。

该研究团队提出一种增益辅助模型来控制反射探测光中的自旋霍尔效应（SHE）。在该模型中，探测光入射到一个含有三能级稀薄气体原子介质的腔中，其中原子与控制场的相互作用遵循双光子拉曼跃迁。研究人员展示了在反常色散和正常色散区域，光子自旋累积的方向可以在布儒斯特角两侧于正值和负值之间切换。

在控制场强度相同的情况下，异常色散区域的光子SHE峰值高于正常色散区域。此外，正常色散区域中布儒斯特角附近的角度范围比反常色散区域更宽。进一步地，通过改变控制场的拉比频率和探测场的失谐量，可以控制光子SHE的峰值和角度范围。基于增益辅助的光子SHE测量可能促进自旋相关的应用，如光学传感。

据悉，在光子自旋霍尔效应（也称为横向偏移）中，由于光的自旋-轨道相互作用，具有相反自旋的入射光光子在横向方向上发生空间分离。

附：英文原文

Title: Gain-assisted control of the photonic spin Hall effect

Author: Muhammad Waseem, Muzamil Shah, Gao Xianlong

Issue&Volume: 2024/09/09

Abstract: In the photonic spin Hall effect (SHE), also known as the transverse shift, incident light photons with opposite spins are spatially separated in the transverse direction due to the spin-orbit interaction of light. Here, we propose a gain-assisted model to control the SHE in the reflected probe light. In this model, a probe light is incident on a cavity containing a three-level dilute gaseous atomic medium, where the interaction between the atom and the control field follows two-photon Raman transitions. We show that the direction of photonic spin accumulations can be switched between positive and negative values across the Brewster angle in both the anomalous and normal dispersion regimes. For the same magnitude of control fields, the peak value of the photonic SHE is higher in the anomalous dispersion region compared to the normal dispersion regime. Additionally, the angular range around the Brewster angle is wider in the normal dispersion regime than in the anomalous dispersion region. Furthermore, the peak value of the photonic SHE and the angular range can be controlled by changing the Rabi frequencies of the control fields and the probe field detuning. The measurement of photonic SHE based on gain assistance may enable spin-related applications such as optical sensing.

DOI: 10.1103/PhysRevA.110.033104

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.033104

来源：科学网 小柯机器人