磁共振系统中自旋极化过程的时间特性
- 2025-05-23 00:16:27
量子光学学报, 2024, 30 (1): 010501, 网络出版: 2024-08-23 复制并引用该论文 被引通知 磁共振系统中自旋极化过程的时间特性【增强内容出版】Time Characteristics of Spin Polarization in Magnetic Resonance SystemGet PDFFull Text图表MetricsMore 董雅宾 1,2,*任磊 1刘博 1张熔石 1杨丽 1康志华 1马强 1王彦华 1
作者单位 1 山西大学 物理电子工程学院 山西 太原 0300062 山西大学 极端光学协同创新中心 山西 太原 030006
光抽运 自旋极化 密度矩阵方程 optical pumping spin polarization density matrix equation OAI 2.0AI高清视频导读 AI一图读本文 AI语音精读 AI语音超短摘要【AI生成本文一句话精读】：本文研究了铷原子在激光抽运磁共振系统中的极化过程时间特性，发现探测光功率越大，原子完成极化的时间越短，实验结果与基于三能级密度矩阵理论的数值分析相符。您的浏览器不支持 audio 元素。AI语音播报 【AI生成本文短摘要】：本文深入探讨了铷原子在激光抽运磁共振系统中的极化过程时间特性，结合理论与实验研究。通过构建实验平台监测透射光强来观察极化状态，发现探测光功率对极化过程有显著影响：功率越大，极化所需时间越短。这一发现得到了基于三能级系统密度矩阵理论的数值分析支持。您的浏览器不支持 audio 元素。AI语音播报 注：本部分内容由 AI 自动生成，仅供您参考。对于您使用本站 AI 自动生成内容所产生的一切后果，本网站及平台运营方概不承担任何商业和法律责任，请您知悉。 摘要本文从理论上和实验上分析了铷原子在静磁场和射频磁场作用下激光抽运磁共振系统中极化过程的时间特性。在我们的实验中，构建了简单的激光抽运实验平台，并通过记录探测光的透射强度监测铷原子的极化状态。射频场关闭时，铷原子通过吸收圆偏共振探测光实现极化，透射光强度达到最大。打开共振射频磁场，极化状态被破坏，即原子会退极化并重新吸收探测光，透射光强度减弱。实验结果表明，探测光功率会影响铷原子实现极化的过程。探测光功率越大，完成极化所需的时间越短。在70 μW到200 μW的探测光功率范围内，铷原子完成自旋极化的时间由33.93 ms缩短到23.37 ms。基于三能级系统的密度矩阵理论数值分析，有力地支持了所提供的实验数据。您的浏览器不支持 audio 元素。AI语音播报 AbstractIn this study, the temporal characteristics of the polarization process of rubidium atoms in a laser pumping magnetic resonance system under the influence of a constant magnetic field and radiofrequency (RF) field are analyzed both theoretically and experimentally. A simple optical magnetic resonance experiment platform has been established based on rubidium atoms in our experiment. By applying a constant magnetic field along the z-direction, Zeeman splitting was induced in rubidium atoms. The frequency of the laser propagating along the z-direction was locked to the saturated absorption spectrum of 85Rb atoms' D1 line transition 52S1/2, Fg=3→52P1/2, Fe=2, and converted into left circularly polarized beam to polarize the atoms. This laser beam was also used as a probe beam to detect the polarization state of rubidium atoms. Meanwhile, a switch-controlled resonant RF field was applied along the x-direction to induce transitions between atomic polarization states. Here, we monitored the polariza-tion state of rubidium atoms by recording the transmission intensity of the probe beam. When the RF field is turned off, rubidium atoms are polarized solely by absorbing left circularly polarized probe beam. The maximum intensity of the transmitted beam indicates that maximum polarization can be achieved in the experiment. When the resonant RF field is activated, the polarization state is disrupted, causing the atoms to depolarize and reabsorb the probe beam, resulting in a decrease in the intensity of the transmitted beam. The minimum intensity of the transmitted beam indicates an equilibrium between the magnetic resonance depolarization process and the optical pumping polarization process. The RF current amplitude was set to 1.8 mA, and the probe beam power increased from 70 μW to 200 μW. The time evolution of transmission beam was observed by periodically switching the current amplitude of the RF coil. Experimental results showed that the power of the probe beam influenced the polarization process of rubidium atoms, with higher probe beam power resulting in shorter polarization completion time. Numerical analysis based on density matrix theory for a three-level system strongly supported the provided experimental data, aiding further investigation into the dynamic evolution of the magnetic resonance system. PDF全文董雅宾, 任磊, 刘博, 张熔石, 杨丽, 康志华, 马强, 王彦华. 磁共振系统中自旋极化过程的时间特性[J]. 量子光学学报, 2024, 30(1): 010501. DONG Ya-bin, REN Lei1, LIU Bo, ZHANG Rong-shi, YANG Li, KANG Zhi-hua, MA Qiang, WANG Yan-hua. Time Characteristics of Spin Polarization in Magnetic Resonance System[J]. Journal of Quantum Optics, 2024, 30(1): 010501.
