Chinese scholars reveal the unique quantum characteristics of "Quantum Cheshire Cat"
Xinhua News Agency, Hefei, July 10 (Reporter Xu Haitao) The thought experiment "Schrodinger's Cat" in quantum mechanics has been widely known in academia. In recent years, the international scientific community has put forward a cutting-edge concept called "Quantum Cheshire Cat". Recently, the team of academician Guo Guangcan from the University of Science and Technology of China and Nankai University scholars have achieved the first separation of the polarization of the photon and its body, and thus the contactless exchange of the polarization of the two photons. The experiment revealed the unique quantum characteristics of the "quantum Cheshire Cat", It has deepened people's understanding of the basic problem of physics, "what is physical reality".
In the macro classic world, the physical properties of objects such as mass and volume are inseparable from the object itself, but they are different in the micro quantum world. A theoretical study in the international scientific community in 2013 showed that the physical properties of microscopic particles (such as the charge and spin of electrons, the polarization of photons, etc.) can be separated from their bodies. Many well-known scholars named this phenomenon as "Quantum Cheshire Cat" .
Cheshire Cat is a grinning cat in the famous children's literary book "Alice in Wonderland". Its body can disappear out of thin air, but the smile is still hanging in the air. In the interference experiment of neutrons and photons in the international scientific community, the phenomenon that the particle properties are separated from their bodies has been observed, but to show the unique quantum effect of "Quantum Cheshire Cat", more complicated experiments are needed.
Recently, Li Chuanfeng, Xu Jinshi, Xu Xiaoye and others in the team of academicians Guo Guangcan of the Chinese University of Science and Technology cooperated with Professor Chen Jingling of Nankai University to realize the exchange of smiling faces of two "quantum Cheshire Cats" for the first time using the dual photonic system.
They used a new method of perturbing the system to solve the problem of weak value extraction in multi-body quantum systems, and prepared two-photon super-entangled states to obtain the weak values of photon paths and polarization observations. In the experiment, it was observed that both photons are in a state of polarization and the body of the photon is separated, and the polarization of the other photon is obtained.
The research results show the flexible and changeable relationship between matter and its physical properties in the quantum world, and deepen people's understanding of the basic physical problem of "what is physical reality". On the other hand, the method of introducing perturbation to obtain weak values will also become a powerful tool for studying quantum physics.
The international authoritative academic journal "Nature·Communications" published the results of this research a few days ago. The reviewers evaluated this as a "milestone" and an important progress in understanding the fundamental problems of quantum mechanics.