Chances are, you've heard about the Schrödinger's cat paradox. We are talking about a hypothetical cat inside a box, which is simultaneously in two states - alive and dead - until we open the box to look. This is the so-called quantum superposition. So, physicists at Yale University figured out how to store both states of a cat in two boxes at once. Scientists shared their work on the pages of Science magazine.
Technically speaking, there is no cat. We are talking about the so-called "cat state", the role of which is played by two (or more) particles that are simultaneously in two different states. For decades, Schrödinger's Cat was just a hypothetical experiment, but in 2005, the US National Institute of Standards and Technology actually successfully created a true “cat state” in a laboratory setting. To do this, they used six atoms in the "spin up state" and in the "spin down state". To make it easier to understand, imagine a clock going clockwise and counterclockwise at the same time. Since then, their experiments with "cat states" have been carried out with photons.
Physicists at Yale University, in turn, were able to reach a new level. They not only used photons in a quantum superposition of states, they also entangled them. That is, in other words, they achieved that when the state of one photon changes, the state of another photon would change, even if they are separated from each other. It should be noted that this is one of the most complex, confusing, and bizarre aspects of quantum mechanics. Albert Einstein once called all this "eerie action at a distance."
"We got two small and simple Schrödinger's cats, both in their boxes and both in a state of entanglement."
To create the fortune, the scientists built a small chamber with two separate aluminum cavities. The microwave photons placed inside began to hit the walls of the cavities, and thanks to this, scientists were able to combine them with an artificial atom of superconducting sapphire. The result is two kind of live / dead cats made of microwave light and are in two different boxes at the same time.
“We've got a big and smart cat. It does not remain in one box, since the quantum state is divided between two cavities and cannot be described separately,”says lead author of the study Chen Wang.
"One could also consider the alternative, in which two small and simple Schrödinger's cats, each in its own box, are confused."
Research like this is very important for the future of quantum computing. Unlike classical computers, which use bits, which are zeros and ones, quantum computers store information in so-called qubits. Qubits, in turn, can be in two states at once - zero and one - just like Schrödinger's cat can be simultaneously in states "alive" and "dead" as long as no one is observing. We can say that the state of superposition is very fragile. Therefore, quantum information must be shielded from any kind of environmental noise. After all, the slightest interference - for example, one photon collides with an atom that is used to encode and store your information - will immediately cause the entire system to “decode”. In other words, the superposition of the quantum state will be lost,which will lead to crashes of the entire system.
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Studying the states that a "cat" can be in is interesting because it can be very useful for storing quantum information. And the ability to create cat states in two different boxes, according to study co-author Robert Scholskoff, is "the first step towards creating a logical operation between two quantum bits and opening up the possibility of error correction."
NIKOLAY KHIZHNYAK