Some predictions regarding pre- and post-selected states are far-reaching, thereby requiring validation with standard quantum measurements in addition to the customary weak measurements used so far, as well as other advanced techniques. We go further pursuing this goal, proposing two thought experiments which incorporate novel yet feasible validation methods of unconventional light-matter interactions. An excited atom traverses a Mach-Zehnder interferometer (MZI) under a special combination of pre- and post-selection. In the first experiment, photons emitted by the superposed atom, after being hit by two laser beams, are individually counted. Despite the interaction having definitely taken place, the numbers of photons emitted from each arm of the MZI are predicted, at the ensemble level, to be different from those expected with standard stimulated emission. In the second experiment, the atom spontaneously emits a photon while still in the MZI. This photon later serves as a strong measurement of the atom's energy upon hitting a photographic plate. The experiment is repeated to enable an interference effect of the emitted photons. Interestingly, the latter gives the appearance that the photons have been emitted by the atom from a position much farther from the two MZI arms L and R, as if in a "phantom arm" R'. These experiments also emphasize the key role of anomalous weak values in determining light-matter interactions. In fact, they present a straightforward realization of an entity we term counter-particles, namely pre- and post-selected states acting as if they have negative physical variables such as mass and energy. The novel verification methods we suggest for testing these predictions resemble weak measurements in some aspects, yet result from definite atomic transitions verified by the detected photons.
Anomalous weak values and contextuality: robustness, tightness, and imaginary parts
弱值是通过涉及弱测量和后选择的量子实验获得的量。它已被证明，“异常”弱值（那些躺在相应的运营商的本征值范围之外）无视经典的解释，在这个意义上，需要上下文[M。F. Pusey，Phys. Rev. Lett. 113，200401，arXiv：1409.1535]。在这里，我们详细阐述和扩展的结果在几个方向。首先，原始定理需要某些完美的相关性，而这些相关性在任何实际实验中都无法实现。因此，我们提供了新的定理，允许从异常的弱值的上下文的噪声鲁棒性的实验验证，并与最近的实验比较。第二，原来的定理连接异常的上下文只有在存在一整套额外的操作约束。在这里，我们澄清了围绕异常弱值的争论，表明这些条件是严格的-如果其中任何一个被丢弃，异常可以被经典地再现。第三，在原来的结果要求弱值的实部是反常的情况下，我们也给出了虚部非零的弱值的一个版本。最后，我们证明了类似的结果，如果弱测量是通过量子比特指针，而不是传统的连续系统。总之，我们提供了不等式证明非经典使用实验现实测量任何异常的弱值，并澄清量子实验的成分必须在任何经典模型，可以重现异常的缺失。
Weak-to-Strong Measurement Transition with Thermal Instabilities: From Anomalous Amplification to Metrological Sensitivity
Universidade Federal do Piauí（皮奥伊联邦大学）；Universidade Federal do ABC（ABC联邦大学）；Southern University of Science and Technology（南方科技大学）；Federal University of Paraná（巴拉那联邦大学）
Magnetically Induced Transparency-Absorption and Normal-Anomalous Dispersion Characteristics of ${}^{87}\text{Rb}$ Medium or Any J-Type Configuration Atomic Vapors Subject to a Vector Magnetic Field and a Weak Resonant Pump
Alikhanyan National Laboratory (Yerevan Physics Institute)（阿利哈尼扬国家实验室（耶烈万物理研究所））；Institute for Physical Research, Armenian National Academy of Sciences（亚美尼亚国家科学院物理研究所）
