How cosmic rays harm quantum computers

quantum computer He must be the next big guru in computer technology. They should greatly improve searches and businesses. Problems that the computer cannot currently handle should be resolved in the shortest possible time.

A quantum processor consists of what is called Quantum bits (qubits) It was built. These qubits can’t just be remembered 1 or 0 It accepts the same as the regular bits, but also accepts the superposition of the two states – i.e. 0 and 1 at the same time. With a full register of qubits, it becomes possible, quite simply, to perform arithmetic operations with several numbers at the same time.

Cosmic rays vs. qubits

One of the biggest challenges in building quantum computers is keeping these qubits stable. For this purpose, superconductors are used, for example, through which qubits are created from electron pairs – the so-called Cooper pairs -. Keeping it stable for longer than a few 100 microseconds is indeed a colossal effort. Superconductors must be cooled very hard so that the electron pairs do not disintegrate. Currently it is still at -273 degrees, absolute zero.

MIT Studies (NaturePhysics) and from Google (NaturePhysics) showed that these pairs of electrons have a big problem: high energy particles, such as cosmic or radioactive radiation. They were hitting the ground regularly and constantly shooting at our bodies. They are also faced with superconductors. Their energy is enough to break up the pairs of electrons. MIT was able to determine this as early as 2020, and now Google is analyzing the problem in more depth.

Error correction is not enough

“It’s not just qubits that suffer, the problem is pervasive. If it’s just localized there won’t be a problem, it’s just an extra error rate to consider. That’s why you correct the error. If all of my qubits suddenly go bad, you can’t correct them anymore” Gerhard Kirchmeier From the Institute of Quantum Optics and Quantum Information of the Academy of Sciences opposite the Future District.

In the setup test by Google, slide with 26 qubits used. Usually, the maximum join is on average 4 One of these qubit errors in a certain period of time. As soon as it hit a high-energy particle, that number increased 24. This is a serious problem for quantum computers working with superconductors, says Kirschmeier. Because every time high-energy particles break up qubits, the process in the quantum computer must be stopped and restarted.

This is not only boring, but also goes against the actual idea, which is high speed. In addition, such an event does not come once a day, but roughly every 10 minutes Before. However, calculations in quantum computers often take several hours.

Look for protection strategies

“It can stop the whole process,” Kirschmayr explains. But it certainly does not mean a knockout of technology. “Now we have to evaluate the strategies that will help protect the particles.” Such a way, for example, data centers of the future huge mountains or deep in the earth to construct. This is perhaps one of the simplest solutions.

Other ideas come from Astrophysics, where one would like to make measurements frequently without cosmic radiation constantly interfering with the result. “One can use other materials that dissipate the particle’s energy and therefore don’t reduce the coherence time of the qubits,” says the physicist. Another option would beLocatedwhich captures the broken electron pairs and does not allow them to escape. After that, they will not affect the other qubits and the process can continue.

“It is likely that a combination of these approaches will be used,” says Kirchmeier. The results did not surprise him. It was already known that cosmic rays and radioactive particles have the ability to disrupt superconductors. However, only a Google study was able to show how amazing the effects actually are. Now we will have to work on the solutions.