论文标题
分散测得的Bose-Einstein冷凝物中的量子反作用极限
Quantum Back-action Limits in Dispersively Measured Bose-Einstein Condensates
论文作者
论文摘要
量子力学的基本原则是，即使不存在观察者，测量结果将系统的波函数变为与测量结果相一致的最一致的波功能。弱测量仅产生有关该系统的有限信息，因此只会最小化系统的状态。在这里，我们从理论上和实验表征了原子bose-Einstein冷凝物与远离谐振激光束相互作用的量子反作用。我们从理论上使用量子轨迹方法来描述这个过程，其中环境测量了散射的光，并根据理想的光反射机制提出了测量模型。我们通过实验量化了与测量过程相关的拉姆西干涉仪和控制寄生效应的对比度，对所得的波函数变化进行了量化。观察到的反作用与我们的测量模型非常吻合。该结果是实现量子气体的真实量子反作用限制测量的必要前体。
A fundamental tenet of quantum mechanics is that measurements change a system's wavefunction to that most consistent with the measurement outcome, even if no observer is present. Weak measurements produce only limited information about the system, and as a result only minimally change the system's state. Here, we theoretically and experimentally characterize quantum back-action in atomic Bose-Einstein condensates interacting with a far-from resonant laser beam. We theoretically describe this process using a quantum trajectories approach where the environment measures the scattered light and present a measurement model based on an ideal photodetection mechanism. We experimentally quantify the resulting wavefunction change in terms of the contrast of a Ramsey interferometer and control parasitic effects associated with the measurement process. The observed back-action is in good agreement with our measurement model; this result is a necessary precursor for achieving true quantum back-action limited measurements of quantum gases.
