In quantum physics, more and more amazing phenomena continue to appear that question our ideas about particles and their properties. One of these phenomena, called the “quantum Cheshire cat”, opens up new horizons in understanding how the properties of particles can exist separately from themselves. For the first time, this phenomenon was described in 2013 in the journal New Journal of Physics. Then the scientists presented the results of the experiment in which the particle seemed to move one way along one path, and its properties were different. This recalled the famous scene from Lewis Carroll’s book “Alice in Wonderland”, where the smile of the Cheshire cat remained in the air, even when the cat himself disappeared.
The essence of the phenomenon is that the properties of the particle, such as its polarization, can “separate” from the particle itself. This was confirmed by experiments that showed that the polarization of the photon moves one way, and the photon itself – in another way. However, like many other quantum phenomena, this concept caused many disputes among physicists. Some scientists question the interpretation of the data itself, insisting that the phenomenon, in fact, is the result of quantum interference, and not the real separation of the particle and its properties.
The key role in the study of this phenomenon was played by the physicist Yakir Aaronov, who was one of the authors first work About quantum Cheshire cat. Aaronov and his colleagues presented a theoretical model in which quantum properties can be transmitted without the participation of a physical particle. Scientists are currently offering the further development of this theory. In the new experiment, it is assumed that the part of the particle can move regardless of the particle itself, which expands the understanding of the quantum nature.
The method proposed by Aaronov includes the intensive repetition of experiments, where the results are grouped and analyzed before and after measurements. This technique allows researchers to track the evolution of the quantum system in time and identify hidden relationships between events. An example is their new experiment in which the particle moves through an interferometer – a device that divides it into two possible paths. Theoretically, scientists argue that it is possible to measure the properties of the particle on one path, while the particle itself will choose another.