Zhou Yan, Shagam Yuval, Cairncross William B, Ng Kia Boon, Roussy Tanya S, Grogan Tanner, Boyce Kevin, Vigil Antonio, Pettine Madeline, Zelevinsky Tanya, Ye Jun, Cornell Eric A
JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
Department of Physics, Columbia University, New York, New York 10027-5255, USA.
Phys Rev Lett. 2020 Feb 7;124(5):053201. doi: 10.1103/PhysRevLett.124.053201.
Cold molecules provide an excellent platform for quantum information, cold chemistry, and precision measurement. Certain molecules have enhanced sensitivity to beyond standard model physics, such as the electron's electric dipole moment (eEDM). Molecular ions are easily trappable and are therefore particularly attractive for precision measurements where sensitivity scales with interrogation time. Here, we demonstrate a spin precession measurement with second-scale coherence at the quantum projection noise (QPN) limit with hundreds of trapped molecular ions, chosen for their sensitivity to the eEDM rather than their amenability to state control and readout. Orientation-resolved resonant photodissociation allows us to simultaneously measure two quantum states with opposite eEDM sensitivity, reaching the QPN limit and fully exploiting the high count rate and long coherence.
冷分子为量子信息、冷化学和精密测量提供了一个绝佳的平台。某些分子对超出标准模型物理学的现象具有增强的敏感性，比如电子电偶极矩（eEDM）。分子离子易于捕获，因此对于灵敏度随探测时间成比例变化的精密测量而言特别具有吸引力。在这里，我们展示了一种自旋进动测量，在量子投影噪声（QPN）极限下实现了秒级相干，使用了数百个被俘获的分子离子，这些分子离子是因其对eEDM的敏感性而被选用的，而非因其对态控制和读出的适应性。取向分辨共振光解离使我们能够同时测量具有相反eEDM敏感性的两个量子态，达到QPN极限并充分利用高计数率和长相干性。
