Nobel Prize in physics goes to trio of researchers for discoveries in quantum mechanics

The 2025 Nobel Prize in physics has been awarded to a trio of scientists – a Briton, a Frenchman and an American – for their ground-breaking discoveries in the field of quantum mechanics.

John Clarke, Michel Devoret and John Martinis will share the prize “for the discovery of macroscopic quantum mechanical tunnelling and energy quantization in an electric circuit,” the Nobel Committee announced Tuesday at a ceremony in Stockholm, Sweden.

The committee praised the laureates for demonstrating that the “bizarre properties of the quantum world can be made concrete in a system big enough to be held in the hand.”

Clarke, taking questions at a news conference, said he was “completely stunned” to learn he had won the award.

“We had not realized in any way that this might be the basis of a Nobel Prize,” Clarke said of their research in the 1980s at the University of California, Berkeley.

Quantum mechanics, which describes how matter and energy behaves at or below the scale of an atom, allows a particle to pass straight through a barrier, in a process called “tunnelling.”

But when a larger number of particles are involved, these quantum mechanical effects usually become insignificant. What is true at the microscopic level was not thought to be true at the macroscopic level. For instance, while a single atom could pass through a barrier, a tennis ball – made up of a huge amount of particles – cannot.

However, the trio of researchers conducted experiments to show that quantum tunnelling can also be observed on a macroscopic scale.

In 1984 and 1985, the trio developed a superconducting electrical system that could pass from one physical state to another, as if a tennis ball could move straight through a barrier and not bounce back.

Anthony Leggett, who won the Nobel Prize in physics in 2003, compared the laureates’ work on how quantum mechanics functions on a larger scale to the famous thought experiment of Erwin Schrödinger, another physics laureate.

To show the paradoxical nature of quantum mechanics, Schrödinger imagined a cat in a sealed box with a device that releases poison when a radioactive source decays. Because there is no way to observe whether the cat is dead or alive, Schrödinger posited that the cat was both dead and alive simultaneously – just as, in quantum mechanics, a system can exist in multiple states at once until measured.

Schrödinger’s thought experiment aimed to show the absurdity of this situation, because quantum mechanics doesn’t make sense on the scale of everyday objects, such as a cat.

Leggett argued, however, that the experiments conducted by Clarke, Devoret and Martinis showed that there are phenomena on larger scales that behave just as quantum mechanics predicts.

Clarke said their research had helped pave the way for technological advances, such as the creation of the cell phone.

“There is no advanced technology used today that does not rely on quantum mechanics, including mobile phones, cameras… and fiber optic cables,” said the Nobel committee.

Last year, the prize was awarded to Geoffrey Hinton – often called the “Godfather of AI” – and John Hopfield, for their fundamental discoveries in machine learning, which paved the way for how artificial intelligence is used today.

In 2023, the prize went to a trio of European scientists who used lasers to understand the rapid movement of electrons, which were previously thought impossible to follow.

The prize carries a cash award of 11 million Swedish kronor ($1 million).

This is a developing story and will be updated.

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