Australian and British scientists have created a quantum analogue of a drum that vibrates and is silent at the same time, much like Schrödinger's cat is alive and dead at the same time, according to an article in the New Journal of Physics.
“In order to learn how to beat the drum, we had to create special quantum sticks, the role of which is played by single particles of light. All this paves the way for creating a mechanical analogue of Schrödinger's cat and testing the laws of quantum mechanics on a macroscale,”said Martin Ringbauer of the University of Queensland in Brisbane, Australia.
Schrödinger's cat is the object of a thought experiment that was proposed in 1935 by the Austrian physicist Erwin Schrödinger. In the experiment, a cat and a mechanism that opens a container with poison in case of decay of a radioactive atom (which may or may not happen) are placed in a closed box. According to the principles of quantum physics, a cat is both alive and dead.
This is where the term "quantum superposition" originates - the totality of all states in which a cat can simultaneously be. Many physicists, including those from the Russian Quantum Center, are now actively trying to create such a Schrödinger's cat that could be seen with the naked eye.
Ringbauer and his colleagues took the first step towards this by studying how single particles of light interact with very thin, but visible films. Scientists wondered whether collisions of photons with these membranes would generate quantum effects that would violate the classical laws of mechanics.
As noted by the physicist, under some conditions, a single particle of light can be cut into two dimmer, but at the same time entangled photons. If one particle is directed at the membrane, and the second at an ordinary mirror, their interaction will lead to the fact that another quantum bond will arise between the drum and the photons.
Quantum drum created by physicists from Australia and Britain / Imperial College London.
At this moment, it comes into play that the sawn photon is actually at the same time at one and the other point - it either flies past the membrane without causing any vibrations in it, or hits it. Accordingly, in some measurements it will beat the drum, while in others it will not cause any changes in it. That is, the drum will simultaneously be silent and knock, and the film becomes a macroscopic analogue of Schrödinger's cat.
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Guided by these ideas, the authors of the article assembled the installation and began to observe the vibrations of the film using another laser. As Ringbauer admits, at room temperatures, this design does not quite resemble a Schrödinger drum, but even under such conditions, anomalies appear on its surface that indicate the presence of quantum properties.
In the near future, Ringbauer's team plans to improve the operation of laser vibration sensors and place a quantum drum in a refrigerator, which they hope will help to see the real Schrödinger's cat for the first time.