The Royal Swedish Academy of Sciences awarded the Nobel Prize in Physics 2025 to John Clarke, Michel H. Devoret and John M. Martinis for the discovery of the Macroscopic Quantum Tunnel effect and the quantification of energy in an electrical circuit.
Quantum mechanics, that branch of physics that governs the behavior of subatomic particles, describes phenomena as strange as tunnelization, a process that allows a particle cross an apparently impassable barrier. Although these effects usually disappear when large amounts of matter intervene, the experiments of the winners with the Nobel Prize in Physics demonstrated that they can also manifest at the macroscopic scale.
To understand the phenomenon, it is enough to imagine a daily scene: when a ball is thrown against a wall, it inevitably bounces. It would be surprising to see her appear on the other side without going through her or breaking it. In quantum mechanics, this type of phenomenon is called a tunnel effect and is precisely the type of phenomenon that has given it the reputation of being strange and not very intuitive.
The winners of the Nobel Prize in Physics 2025 used a series of experiments to demonstrate that the strange properties of the quantum world can be completed in a system large enough to hold it in hand. Its superconductor electrical system could pass from one state to another through a tunnel effect, as if crossing a wall. They also demonstrated that the system absorbed and emitted energy in specific doses, such as quantum mechanics.
In 1984 and 1985, John Clarke, Michel H. Devoret and John M. Martinis performed a series of pioneer experiments with a circuit built with superconductors, Materials capable of conducting electricity without resistance. The scientists separated the components by a thin insulating layer, forming a Josephson union, and managed to observe how the currents that They circulated In the circuit they behaved collectively as a single particle that covered the entire system.
That macroscopic system but governed by quantum laws, could remain in a stable state without generating voltage, as if they were caught after an invisible barrier. However, the researchers showed that it was able to “escape” from that state through the tunnel effect, an unequivocally quantum characteristic.
The results confirmed that the system was quantized, That is, it could only absorb or emit energy in discrete quantities, as predicts quantum theory.
“It is wonderful to celebrate how quantum mechanics, with a century of history, continues to offer surprises and applications. It is the basis of all modern digital technology, ”said Olle Eriksson, president of the Nobel Committee of Physics.
Microchips transistors, for example, are the result of quantum principles already consolidated. But the experiments of the winners open The door to a new generation of technologies: quantum computers, inviolable cryptography and extreme precision sensors.
The winners
John Clarke was born in 1942 in Cambridge, the United Kingdom. He obtained his doctorate in 1968 at the University of Cambridge and is currently a professor at the University of California, in Berkeley, United States.
Michel H. Devoret, born in 1953 in Paris, France, was a doctorate in 1982 at the Paris-Sud University. He is a professor at Yale University, in New Haven, Connecticut, and has also worked as a professor at the University of California, in Santa Barbara.
John M. Martinis, born in 1958, won his doctorate in 1987 at the University of California, Berkeley. He is currently a professor at the University of California, Santa Barbara.
