Researchers affiliated with Google have presented the first truly advanced quantum calculation. A business that, in the long run and according to several analysts, may change the world.
– This is clearly a milestone, says Professor Per Delsing.
– But at the technology company IBM, you can keep yourself laughing.
It was in the journal Nature that the researchers presented their breakthrough. By using a so-called quantum computer, they have managed to perform a calculation that took just over three minutes, or 200 seconds, to perform. A calculation that for a regular computer, even if it is the world’s fastest, would take at least 10,000 years.
We see what Google has done as something very important. As a milestone, says Per Delsing, professor of physics at Chalmers University of Technology and head of quantum research at the Wallenberg Center in Gothenburg.
A common computer represents information in the form of strings of binary numbers 1 and 0. In a quantum computer, on the other hand, quantum bits are used instead, where each quantum bit is a quantum particle with two possible quantum states, so that 1 and 0 can be represented by these states.
Several permits
The tricky thing is, however, that each quantum bit can also be in an arbitrary (coherent) overlay of these two states and thus carry more information than just 1 and 0. In addition, the quantum bits can be heaped, allowing very special opportunities for a quantum computer to perform calculations, compared to a regular computer.
In this way, quantum supremacy can be achieved, that is, a computer far superior to a regular computer, even though a quantum computer cannot perform calculations other than a regular computer. It can only do them in a different way, and above all, faster.
But calculating with the help of single quantum particles is difficult. Therefore, the researchers have used superconducting circuits instead.
– When the circuit is superconducting, there is no resistance (resistance) and then you can build the circuit so that it behaves quantum mechanically, that is, atoms, where each circuit acts as an artificial atom, says Per Delsing.
Impossible calculations
Each circuit thus becomes a quantum bit and the current experiment consisted of a computer with 53 quantum bits.
– We are developing an exact same quantum computer used in the experiment. We don’t have as many circuits yet, but this shows that we are on the right track, says Per Delsing.
The researchers at Google let the quantum computer calculate an algorithm that, according to the company, would take 10,000 years for the world’s fastest computer, IBM’s “Summit,” to execute. It took 200 seconds for the new quantum computer.
– The algorithm itself does not make anyone happy. It had only been developed to show that it works. On the other hand, you can think of areas where a quantum computer can be very useful, for example to solve optimization problems, says Per Delsing.
Imagine, he says, that you have 100 aircraft, 100 destinations and 100 aircraft crews. How should you combine these to make it as cost effective as possible?
– The number of possible combinations will be ten increased to 315. That is one after 315 zeros. Allowing an ordinary computer to count on it would take longer than the age of the universe, but with a quantum computer it would go much faster, says Per Delsing.
Sour mines at IBM
However, the technology company IBM is not so happy about the negative attention and says in a statement that the proposed algorithm would only take 2.5 days for “Summit” to calculate, not 10,000 years.
Regardless, says Per Delsing, it doesn’t speed up the Google scientists’ business.
– 200 seconds is still good much faster than 2.5 days. I have read the article and I think the research seems to be very solid, he says.
But unlike ordinary computers, quantum computers are extremely sensitive, which is why it will take a long time before they become each man’s property.
– It took a good while before the transistor came to be used by computers. It often takes a long time like this, not often decades, says Per Delsing
