"What we predicted is starting to happen." The physicist Juan Ignacio Cirac, director of the theoretical division of the Max Planck Institute for Quantum Optics, based in Munich (Germany), is considered one of the fathers of quantum computing, the disruptive technology that promises to change the world as it once did. Faraday's experiments did it. Quantum computers can solve problems that would take classical computers millions of years. "It is a revolution, but revolutions take time and the most important thing is yet to be discovered," said the researcher, Prince of Asturias Prize winner in 2006 and Wolf Prize winner in 2013 - considered a prelude to the Nobel Prize. With him the cycle has been inaugurated
Future Dialogues
, organized by ABC and the La Caixa Foundation to reflect with the help of prestigious specialists in science, research and the environment on transcendental issues for society.
Asked by José Manuel Nieves, a journalist specialized in science and technology, Cirac acknowledged that it is very difficult to predict how quantum computing will impact society, "in the same way that when the Internet appeared we did not know what it represents today."
As he explained, quantum computers solve the same problems as classical computers, but in a different way, with other laws of physics. They are the laws of the microscopic world, in which things as incredible as quantum superposition happen, "the first shock" when someone approaches this field. Cirac compares it to touching the foot of an elephant without having ever seen it. «These laws tell us that a particle can be in two places at the same time. But if we observe it, that capacity disappears. Taking it to the macroscopic world, it is as if the Moon is not there when we are not looking at it. This drove Einstein crazy,” he explains. And if the genius had a hard time accepting it, for the rest of us it seems like science fiction. When he was doing his doctorate, Cirac tried to explain it to his grandmother, from a village in Galicia. He didn't want his grandson to be laughed at: "'Great Ignacio, very good, but don't tell anyone,' he told me."
More than atoms in the universe
But when scientists see extraordinary properties, they try to do extraordinary things with them. If a classical computer processes information in zeros and ones, in a quantum computer, each qubit or quantum bit can be zero and one at the same time. And therein lies its power. «We play with that world in which all things happen at once. And that is much faster," he points out. Of course, building quantum computers is terribly complicated, since the qubits have to be isolated in order to preserve their superpositions. A computer with 200 qubits has already been obtained at Harvard University. It doesn't look very impressive, but its capacity is exponential. «If we had 300, the number of combinations would be greater than the number of atoms in the universe. “It could do a better calculation than any computer we have right now,” says the physicist.
Cirac chats with journalist José Manuel Nieves
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ABC
Will there come a time when we all have a computer like this at home? Cirac is not entirely convinced, since he cannot imagine why we would need that computing power if we are dedicated to surfing the Internet or sending emails. "Although we do not know what the needs of consumers will be in thirty years," he clarifies.
What these machines will be used for is to solve calculations in the field of physics, chemistry - such as drug development -, artificial intelligence applications... Or for optimization problems: for example, what route should a traveling salesman take? Visit 50 cities to spend as little time as possible.
China's dominion
Cirac recalls that Google achieved quantum supremacy in 2019 (when a quantum computer performs a task that is beyond the reach of the most powerful conventional supercomputer) and that China has managed to surpass the internet giant, starting a race in which, he warns, Europe cannot be left behind. «It would be dangerous for countries that are not democratic to be ahead. It is important that we provide not only academic support for this research but also a boost to the industry,” he says. One of the risks, for example, would be the lack of protection of encrypted communications against quantum computers, something that could occur within a decade and for which we will have to prepare.
The researcher believes that in three years we will see practical quantum applications (Google's result was just an academic calculation) and in the next step, within ten years, quantum computers will no longer have errors, something very common now. When British Chancellor of the Exchequer Gladstone questioned Faraday about the practical usefulness of electrical energy, Faraday replied: "Sir, one day you will be able to tax it." Cirac believes the same could happen with quantum computing.