Precision Measurements with Ultra-Sensitive Magnetometers and Their Fundamental Limits

该项目将侧重于使用自旋极化原子测试基本对称性。将开发一种使用K、Rb和Ne-21原子的共磁强计，以寻找CPT和洛伦兹对称性的违反。使用核自旋为3/2的Ne-21原子将允许搜索保留CPT但违反洛伦兹对称性的异常相互作用。共磁强计的极高能量分辨率也将允许搜索异常自旋-自旋和自旋-质量力，对轴子和其他拟议的轻粒子施加新的约束。预计在许多情况下，实验的灵敏度将受到量子涨落的限制，而另一组实验将被用来理解稠密碱金属蒸气中的这些限制。这些实验的成功完成将对一些试图解释宇宙中暗物质和暗能量的理论提出新的限制，并发展一个完整的量子力学引力理论。它还将导致磁场和惯性旋转的新测量技术的发展，可能的应用超出物理学。特别是，在低浓度下检测单个单域纳米颗粒将使生物学中新的单分子计数实验成为可能。一些研究生、本科生和高中生将接受各种研究技术的培训，从超低噪声电子设备的建造到粒子物理学背景下原子测量的解释。

The project will focus on tests of fundamental symmetries using spin-polarized atoms. A co-magnetometer using K, Rb and Ne-21 atoms will be developed to search for violations of CPT and Lorentz symmetries. Using Ne-21 atoms with a nuclear spin of 3/2 will allow searches for anomalous interactions that preserve CPT but violate Lorentz symmetry. Very high energy resolution of the co-magnetometer will also allow searches for anomalous spin-spin and spin-mass forces, placing new constraints on axions and other proposed light particles. It is anticipated that the experimental sensitivity in many cases will be limited by quantum fluctuations and a separate set of experiments will be conducted to understand these limits in dense alkali-metal vapors.Successful completion of these experiments will result in new constraints on a number of proposed theories seeking to explain dark matter and dark energy in the Universe and to develop a fully quantum-mechanical theory of gravity. It will also result in development of new measurement techniques for magnetic fields and inertial rotation, with possible applications beyond physics. In particular, detection of individual single-domain nano-particles at low concentrations will enable new single molecule counting experiments in biology. A number if graduate, undergraduate and high-school students will be trained in various research techniques, ranging from construction of ultra-low noise electronics to interpretation of atomic measurements in the context of particle physics.