基于铷原子系综的等温剩磁检测系统研究

等温剩磁(isothermal remanent magnetization,IRM)是物质磁性测量分析的重要研究内容之一.然而,常用的等温剩磁测量系统因测量灵敏度低、体积庞大且维护成本高等问题无法满足实际使用要求.因此,设计并研制测量精度高且便于使用的小型化等温剩磁检测系统成为必然,其中,基于铷原子系综的磁场测量技术具有灵敏度高、易小型化等优点.利用该磁场检测技术,设计并搭建了等温剩磁检测系统,着重介绍了磁化装置、剩磁检测装置等核心部件的设计方案,并成功地对采自华东师范大学闵行校区樱桃河附近表层土壤进行了检测,实现了该土壤等温剩磁曲线的测量.研究表明,该系统操作容易且便于维护,在环境磁学、地质勘探和生物磁场测量领域有很重要的应用前景。

Parametric amplification of Rydberg six- and eight-wave mixing processes

We study the parametric amplification of electromagnetically induced transparency-assisted Rydberg six-and eight-wave mixing signals through a cascaded nonlinear optical process in a hot rubidium atomic ensemble both theoretically and experimentally. The shift of the resonant frequency(induced by the Rydberg–Rydberg interaction) of parametrically amplified six-wave mixing signal is observed. Moreover, the interplays between the dressing effects and Rydberg–Rydberg interactions in parametrically amplified multiwave mixing signals are investigated. The linear amplification of Rydberg multiwave mixing processes with multichannel nature acts against the suppression caused by Rydberg–Rydberg interaction and dressing effect.