Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris-Sud, 2 avenue Augustin Fresnel, 91127 Palaiseau, France.
Phys Rev Lett. 2013 May 24;110(21):210503. doi: 10.1103/PhysRevLett.110.210503. Epub 2013 May 23.
We demonstrate how to use feedback to control the internal states of trapped coherent ensembles of two-level atoms, and to protect a superposition state against the decoherence induced by a collective noise. Our feedback scheme is based on weak optical measurements with negligible backaction followed by coherent microwave manipulations. The efficiency of the feedback system is studied for a simple binary noise model and characterized in terms of the trade-off between information retrieval and destructivity from the optical probe. We also demonstrate the correction of more general types of collective noise. This technique can be used for the operation of atomic interferometers beyond the standard Ramsey scheme, opening the way towards improved atomic sensors.
我们展示了如何利用反馈来控制被俘coherent 原子 ensemble 的内部状态，并保护叠加态免受集体噪声引起的退相干。我们的反馈方案基于弱光学测量，其反馈作用可以忽略不计，随后进行相干微波操作。我们研究了简单二进制噪声模型下反馈系统的效率，并根据光学探针的信息检索和破坏性之间的权衡来对其进行了描述。我们还展示了对更一般类型的集体噪声的修正。该技术可用于超越标准 Ramsey 方案的原子干涉仪的操作，为改进原子传感器开辟了道路。
