基于光场-原子自旋压缩态的高精度磁场测量实验研究

项目名称： 基于光场-原子自旋压缩态的高精度磁场测量实验研究

项目编号： No.11274118

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 陈丽清

作者单位： 华东师范大学

项目金额： 95万元

中文摘要： 超高精度的磁场测量技术在很多科学研究、工业、生物和医药应用等领域有着广泛的应用。目前国际上测量精度最高的磁力计是原子磁力计。经典的原子磁力计采用普通的相干光和原子池，分别给测量系统带来光极化噪音和原子投影噪音，两者大小相当，已经成为了高精度磁场测量的挡路石。为了降低噪音，2010年Polzik和Mitchell小组分别采用原子自旋压缩态和光极化压缩态来减小原子投影噪音和光场极化噪音，将系统噪音减小至标准量子限以下。目前国际上还没有方案提出同时降低原子和光场带来的噪音。本项目正是针对这一研究现状，在我们前期研究基础上，提出原创性实验方案，并从实验上获得突破。其原理是用相干拉曼散射在原子系综中制备出光-原子自旋量子压缩态，可同时降低光与原子的噪音，再对压缩态进行量子操作，提高系统信噪比，量子测量磁场大小。本项目成果不仅将改善原子磁力计的精度，而且将丰富量子光学的科学内容。

中文关键词： 量子精密测量；光-原子关联；光-原子混合干涉；拉曼散射；磁场测量

英文摘要： The ability to measure magnetic fields with high precision is a key requirement in many physical,biological and medical applications.Atomic magnetometers based on atomic ensembles are currently the most precise devices.Two distinct sources of quantum noise determine the fundamental precise of this technique: the atomic projection noise and the optical polarization noise.These two noise has limit the development of the megnetometer.In order to reduce the noise, Polzik and Mitchell have applied the spin squeezing state and a polarization-squeezed light to improve the preciseion of the magnetometer, they reduced the noise below the shot noise limit.Nowaday, there isn't experimental research to reduce the two noises at the same time.Based on our previous research,we put forward our own proposal. We use coherent Raman scattering to produce the sequeezed state between the atomic spin and polarized light, the sequeezed state could reduced the two kinds of noise at the same time. We will manipulate the sequeezed state to increase the system signal-to-noise ratio and measure the magnetic field. The result of the application will not only improve the precision of the magnetometer, but also enrich the scientific content of the quantum optics.

英文关键词： quantum precision measurement；ligh-atom correaltion；light-atom hybrid interferometer；Raman scattering；magnetic measurement