Palacios Alvarez Silvana, Gomez Pau, Coop Simon, Zamora-Zamora Roberto, Mazzinghi Chiara, Mitchell Morgan W
ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
Quantum Computing and Devices (QCD) Labs, Department of Applied Physics, Aalto University and Quantum Technology Finland (QTF) Centre of Excellence, FI-00076 Aalto, Finland.
Proc Natl Acad Sci U S A. 2022 Feb 8;119(6). doi: 10.1073/pnas.2115339119.
We present a magnetic sensor with energy resolution per bandwidth [Formula: see text] We show how a Rb single-domain spinor Bose-Einstein condensate, detected by nondestructive Faraday rotation probing, achieves single-shot low-frequency magnetic sensitivity of 72(8) fT measuring a volume [Formula: see text] for 3.5 s, and thus, [Formula: see text] We measure experimentally the condensate volume, spin coherence time, and readout noise and use phase space methods, backed by three-dimensional mean-field simulations, to compute the spin noise. Contributions to the spin noise include one-body and three-body losses and shearing of the projection noise distribution, due to competition of ferromagnetic contact interactions and quadratic Zeeman shifts. Nonetheless, the fully coherent nature of the single-domain, ultracold two-body interactions allows the system to escape the coherence vs. density trade-off that imposes an energy resolution limit on traditional spin precession sensors. We predict that other Bose-condensed alkalis, especially the antiferromagnetic Na, can further improve the energy resolution of this method.
我们展示了一种每带宽能量分辨率为[公式：见正文]的磁传感器。我们展示了通过无损法拉第旋转探测检测到的铷单畴自旋玻色 - 爱因斯坦凝聚体如何在测量体积为[公式：见正文]的情况下，在3.5秒内实现72(8) fT的单次低频磁灵敏度，因此，[公式：见正文]。我们通过实验测量凝聚体体积、自旋相干时间和读出噪声，并使用相空间方法，在三维平均场模拟的支持下，计算自旋噪声。对自旋噪声贡献包括一体和三体损耗以及由于铁磁接触相互作用和二次塞曼频移的竞争导致投影噪声分布的剪切。尽管如此，单畴超冷两体相互作用的完全相干性质使系统能够避免在传统自旋进动传感器中施加能量分辨率限制的相干性与密度的权衡。我们预测其他玻色凝聚碱金属，特别是反铁磁钠，可以进一步提高该方法的能量分辨率。
