发表机构
University of Toronto（多伦多大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文首次实现原始弱斯特恩-盖拉赫实验，通过后选择放大弱磁动量冲击，测量到异常弱值，验证了弱值理论。
AI 中文摘要
算子的弱值是给定初始和最终状态下对量子系统测量该算子的平均结果。这些状态之间的重叠出现在弱值的分母中，因此如果该重叠很小，弱值可以任意大。1988年，Albert、Aharonov和Vaidman提出了一种弱斯特恩-盖拉赫实验，该实验能够测量所谓的异常弱值，即测量结果位于被测算子的特征值谱之外。尽管异常弱值已在众多光学系统中被测量，这里我们首次实现了该实验的原始提议。通过将87Rb的玻色-爱因斯坦凝聚体置于磁场梯度中并进行一次不太可能的后选择，我们测量了弱磁动量冲击（约8微米/秒）的有效放大倍数为14倍。我们还证明，增加动量冲击会降低测量的“弱性”并减少放大效果。
英文摘要
The weak value of an operator is the average result of measuring that operator on a quantum system given specified initial and final states. The overlap between these states appears in the denominator of the weak value, and thus if that overlap is small, the weak value can be arbitrarily large. In 1988, Albert, Aharonov, and Vaidman proposed a weak Stern-Gerlach experiment which would be able to measure a so-called anomalous weak value, a measurement result which lies out- side of the eigenvalue spectrum of the operator being measured. Though anomalous weak values have been measured in numerous optical systems, here we present the first such realization of this experiment as originally proposed. By placing a Bose-Einstein condensate of 87Rb in a magnetic gradient and performing an unlikely postselection, we measure an effective magnification of a weak magnetic momentum kick (~ 8 $μ$m/s) by a factor of 14. We also demonstrate that increasing the momentum kick decreases the "weakness" of the measurement and reduces the amplification.
Comments6 pages, 3 figures
