how the award-winning study could lead to the supercomputer of the future

This Tuesday, the 4th, the winners of the 2022 Nobel Prize in Physics were announced, which had quantum mechanics as the star of research in the field. Scientists Alain Aspect from France, American John F. Clauser and Austrian Anton Zeilinger are credited with discoveries that could help build supercomputers of the future that use the principles of quantum physics for their work – a field known as quantum computing.

The study of the Nobel laureate is directly related to the concept of the so-called quantum entanglement (or quantum entanglement), which allows shortening the way in which data can circulate between quantum computers. By using entanglement, the quantum chips achieve a stable connection so that at these moments they will always be connected to each other, no matter how far apart they are.

“It was discovered that entanglement is not just a property of quantum physics, but a physical resource that can be used to create things,” says Fernando Brandão, a professor in the Department of Physical Theory, Physics, Mathematics and Astronomy at the California Institute of Technology (Caltech). “It is a very important experiment from the point of view of fundamental physics and the fundamentals of physics.”

This means that the information contained in one particle can be instantly transferred to another, as if it were the same particle. This transfer of information in the entanglement is called quantum teleportation.

“These correlations cannot be described mathematically in the same way we describe the correlations that appear in classical systems, and therefore generate new phenomena that seem counterintuitive to us who are used to directly interacting only with classical systems. On the other hand, they enable the development of new technologies. For this reason, entanglement is considered a valuable resource in quantum information and computing,” explains Bárbara Amaral, quantum information researcher at the Physics Institute of the University of São Paulo, for Estadão.

In classical computing, bits (the smallest units of information) work in binary and are represented by 0 or 1. In classical computing, quantum bits (or qubits) can take on numerous states between 0 and 1, in a phenomenon called superposition.

This behavior exponentially increases the amount of information that can be processed at the same time. While a traditional pair of bits expresses one type of information at a time, two quantum bits can express (ie have) four states at the same time. It is estimated that 300 qubits express a number of states greater than the number of atoms in the universe.

“It is difficult to test these inequalities experimentally. For their execution, it is necessary to assume several conditions that are difficult to guarantee in a real scenario”, explains Barbara. “Clauser’s work was important in finding a very simple inequality, as simply as possible, and then his and Aspect’s work were pioneers in trying to experimentally demonstrate the violation of this inequality,” she says of the work of Tuesday’s honorees.

The big problem they face in this area is that qubits are very unstable, resulting in small moments of “alignment” of these points. As interleaving only occurs when there is superposition, the information transfer windows are also short. This is a challenge for technology scientists.

In tests conducted in 2017, the University of Bristol was able to perform this teleportation between particles for the first time in the laboratory. At Delft University of Technology in the Netherlands, a team of physicists has also successfully tested “quantum teleportation” to send data from quantum machines to three physical locations.

It is estimated that between 100,000 and 1 million qubits are needed for a machine with practical applications. But the path to developing chips with thousands of qubits is complex: the most famous machine of its kind, Google’s Sycamore chip, had only 53 qubits.

The importance of discoveries in this area is the development of machines capable of processing information that is not possible with our computers today. This can benefit industry and research in medicine, disease, climate and environmental monitoring, cyber security and financial systems.

In 2019, a Google search for quantum chips solved in 2 minutes a mathematical problem that would take 10,000 years to solve on a classical machine. However, there is still a long way to go for these machines to be used in real life. The studies that won the Nobel Prize on Tuesday therefore enable these supercomputers to communicate – this is the way to a kind of “internet of the future”.

“Due to experimental difficulties, not all conditions necessary for deriving the inequality were met in the experiment. These problems are known as ‘loopholes’. A no-loop experiment was required for conclusive proof of quantum inequality violation. This happened in 2015, with experiments by Zellinger’s group and also by a group in the Netherlands,” explains Barbara.

The scientists will share the prize, which totals 10 million Swedish kronor (or about R$4.8 million). The announcement of the physics prize follows the prize in medicine, announced this Monday the 3rd, which went to Svante Pääbo of Sweden for his studies on human evolution. Prizes for chemistry, literature, peace and economics will be announced in the coming days.