Nobel Prize 2025 in Physics goes to John Clarke, Michel Devoret and John Martinis

The Nobel Prize 2025 in Physics was awarded to John Clarke, Michel Devoret and John Martinis on Tuesday (October 7) “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit".

In his first reaction after receiving the award, new physics laureate John Clarke said he was surprised when he discovered he had been awarded this year's Nobel Prize in Physics.

“I’m completely stunned, it never occurred to me that it would be the basis of a Nobel Prize," he said.

At this morning's press conference, he reflected on his prize-awarded research: “Our discovery is in some way the basis of quantum computing."

Nobel Prize 2025 in Physics: What were they awarded for?

This year’s Nobel Prize in Physics recognises experiments that demonstrated how quantum tunnelling can be observed on a macroscopic scale, involving many particles.

The Nobel Prize laureates in physics for 2025, John Clarke, Michel H. Devoret and John M. Martinis, used a series of experiments to demonstrate that the bizarre properties of the quantum world can be made concrete in a system big enough to be held in the hand.

John Clarke, Michel Devoret and John Martinis – awarded this year’s Nobel Prize in Physics – constructed an experiment using a superconducting electrical circuit.

The chip that held this circuit was about a centimetre in size. Previously, tunnelling and energy quantisation had been studied in systems that had just a few particles.

Here, these phenomena appeared in a quantum mechanical system with billions of Cooper pairs that filled the entire superconductor on the chip.

In this way, the experiment took quantum mechanical effects from a microscopic scale to a macroscopic one.

What are quantum mechanics and tunnelling?

Tunnelling is a quantum mechanical process, which entails that chance plays a role. Some types of atomic nuclei have a tall, wide barrier, so it can take a long while for a piece of the nucleus to appear outside it, while other types decay more easily.

Quantum mechanics describes properties that are significant on a scale that involves single particles. In quantum physics, these phenomena are called microscopic, even when they are much smaller than can be seen using an optical microscope.

This contrasts with macroscopic phenom­ena, which consist of a large number of particles. For example, an everyday ball is built up of an astronomical number of molecules and displays no quantum mechanical effects. We know that the ball will bounce back every time it is thrown at a wall.

A single particle, however, will sometimes pass straight through an equivalent barrier in its microscopic world and appear on the other side. This quantum mechanical phenomenon is called tunnelling.