We report a novel method to prepare a mixture of ⁴⁰K Fermi gas having an equal population of the two ground magnetic spin states confined in an optical dipole trap, in the presence of an noisy quantization (magnetic) field. We realize the equal population mixture by applying a series of RF pulses. We observe the dependence of the population distribution between two spin states on the number of the applied RF pulses and find that the decoherence effects leading to the population fluctuations are overcome by the high number of RF pules. Our demonstrated technique can be potentially used in the precision measurement experiments with ultracold gases in noisy environments.

我们报告了一种新方法来制备⁴⁰ K 费米气体的混合物，该气体具有相同数量的两个基磁自旋态，限制在光偶极陷阱中，存在噪声量化（磁场）场。我们通过应用一系列射频脉冲来实现等量混合。我们观察了两个自旋状态之间的种群分布对施加的 RF 脉冲数量的依赖性，并发现导致种群波动的退相干效应被大量 RF 脉冲所克服。我们展示的技术有可能用于嘈杂环境中超冷气体的精密测量实验。