CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Phys Rev Lett. 2019 Oct 11;123(15):150402. doi: 10.1103/PhysRevLett.123.150402.
Entanglement and the wave function description are two of the core concepts that make quantum mechanics such a unique theory. A method to directly measure the wave function, using weak values, was demonstrated by Lundeen et al. [Nature 474, 188 (2011)]. However, it is not applicable to a scenario of two disjoint systems, where nonlocal entanglement can be a crucial element, since that requires obtaining weak values of nonlocal observables. Here, for the first time, we propose a method to directly measure a nonlocal wave function of a bipartite system, using modular values. The method is experimentally implemented for a photon pair in a hyperentangled state, i.e., entangled both in polarization and momentum degrees of freedom.
纠缠和波函数描述是使量子力学成为独特理论的两个核心概念。伦丁等人[自然 474, 188 (2011)]展示了一种使用弱值直接测量波函数的方法。然而，它不适用于两个不相交系统的情况，在这种情况下，非局域纠缠可能是一个关键要素，因为这需要获得非局域可观测量的弱值。在这里，我们首次提出了一种使用模值直接测量双粒子系统的非局域波函数的方法。该方法在一个超纠缠态的光子对中进行了实验实现，即偏振和动量自由度都纠缠。
