Physicists have learned to accurately predict the failure time of a quantum system

Physicists for the first time were able to accurately predict the future of quantum systems - more precisely, the moment when these systems collapse - long before it actually happens. This important opportunity can be used to create very powerful, more accurate and more reliable quantum technologies in the future.

If you do not understand what is going on in the previous paragraph, then here's a simpler example. Take, for example, your smartphone. You are well aware that one day this device will fail, because this always happens with technology. Now imagine that you can predict the exact time in the future when this happens, and also be able to avoid this moment until it has come. This is what physicists from Australia have learned. Only instead of mobile phones, they learned to accurately predict the future breakdown of quantum systems and talked about how to prevent it.

The main distinguishing feature between the breakdown of a smartphone and a quantum system is that the quantum system breaks down much faster and, more importantly, it happens much more "accidentally" than with smartphones.

"As with every single component in a mobile phone, which sooner or later fails, the same is true for quantum systems. However, in quantum technology, the lifespan is most often a matter of fractions of seconds, not years, as in the case of a mobile device, "explains Michael J. Birkak, head of research at Sydney University.

Quantum technologies like quantum computers have the potential to make a real revolution in our life and work. Our usual computers for processing information rely on a binary system, where the values ​​of bits (elementary units of information) take the form of digital "zeros" and "units". Quantum bits (or qubits) in turn consist of atoms sealed in tiny chips. They can either be "on" or "off", and also be in a third state called "superposition", which makes them even more effective. However, one of the cornerstones of quantum technologies is that they can not be called reliable, because the very environment in which the qubits are located can chaotically change their state, causing decoherence. In other words, this means that at a random point in time quantum systems may lose their "quantumness", becoming useless.

To date, scientists, because of the specific nature of the problem of exposure to random factors, there was no way and no way to predict when exactly this "random point in time" would come. The complexity in solving this problem also imposed the specificity of the fact that you can not measure quantum systems without their actual destruction.

"People very often use the methods of forecasting in everyday life. For example, when we play tennis, we predict where the tennis ball will go after the blow according to our observations and the aerodynamic characteristics of the ball itself, "says Birkak.

These predictions work, because rules and physical laws, of the same gravity for example, are able to predict its behavior.

"However, imagine that all these rules and laws were randomly changed while this ball flew to you? In this case, it is impossible to predict its further behavior, "Birkak continues.

"And yet this situation accurately describes what we have to face in our work, because the disintegration (decay) of quantum systems is a random event. Moreover, in quantum reality, the very observation of the object erases its property of quantumness, so our team had to seriously think about how and when such a system might accidentally break down. We actually had to hit that chaotically flying tennis ball, while being blindfolded. "

To solve this issue, a team of scientists from Sydney University used machine learning - the same set of computer algorithms that are used to process huge amounts of data - to find any information that could help them predict when the qubits fail.

It turned out that no matter how random quantum systems seem to be for us, they contain enough information for computer algorithms to try to calculate how a particular qubit will change in the future, and without direct observation, it is predicted when it will collapse. After physicists compared these predictions to cases where real qubits failed, they found that these predictions were surprisingly very accurate. Moreover, it turned out that these predictions are able to compensate for possible changes that could lead to the destruction of the quantum system.

Further, if the researchers learn to do this in real time, this will make the qubits much more reliable and stable, and also help quantum computation to come much closer to reality.

"We are perfectly aware that the creation of real quantum technologies will require from us outstanding capabilities to control and stabilize qubits in order to make their use useful. We can not wait to develop new opportunities that will turn quantum systems from sci-fi wonders into useful technologies. The quantum future is becoming more distinct, "Birkak sums up.

The article is based on materials https://hi-news.ru/technology/fiziki-nauchilis-tochno-predskazyvat-moment-vyxoda-iz-stroya-kvantovoj-sistemy.html.