The 2025 Nobel Prize in Physics has been awarded to John Clarke, Michel H. Devoret, and John M. Martinis for their pioneering experiments demonstrating quantum mechanical effects in electrical circuits – work that has paved the way for the next generation of quantum technologies.

The Royal Swedish Academy of Sciences announced the award in Stockholm, recognising the trio “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.” Their work, conducted in the 1980s, revealed that the strange laws of quantum mechanics could be observed not just at the atomic scale, but within systems large enough to hold in one’s hand.

U.S.-based physicists Clarke, Devoret, and Martinis carried out their experiments using superconducting electrical circuits known as Josephson junctions – where two superconductors are separated by a thin insulating layer. By passing a current through these circuits and measuring the resulting quantum phenomena, they were able to demonstrate two key effects: quantum tunnelling, where particles pass through barriers that should be impenetrable, and energy quantisation, where the system absorbs or emits energy only in discrete amounts.

BREAKING NEWS
The Royal Swedish Academy of Sciences has decided to award the 2025 #NobelPrize in Physics to John Clarke, Michel H. Devoret and John M. Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.” pic.twitter.com/XkDUKWbHpz

— The Nobel Prize (@NobelPrize) October 7, 2025

These findings offered the first concrete demonstration that quantum mechanical properties can appear on a macroscopic scale, challenging assumptions about the limits of quantum behaviour. The laureates’ work has since become a cornerstone for technologies including quantum computers, quantum cryptography, and quantum sensors.

“It is wonderful to be able to celebrate the way that century-old quantum mechanics continually offers new surprises. It is also enormously useful, as quantum mechanics is the foundation of all digital technology,” said Olle Eriksson, Chair of the Nobel Committee for Physics.

Professor John Clarke, born in Cambridge and now based at the University of California, Berkeley, said the award came as “the surprise of my life.” Speaking by phone to the Nobel press conference, he added: “My feelings are that I’m completely stunned. Of course it had never occurred to me in any way that this might be the basis of a Nobel Prize.”

He continued, “I’m speaking on my cell phone and I suspect that you are too, and one of the underlying reasons that the cell phone works is because of all this work.”

Michel H. Devoret, born in Paris, is a professor at Yale University and the University of California, Santa Barbara, while John M. Martinis is also a professor at the University of California, Santa Barbara. The three will share the 11 million Swedish kronor (£872,000) prize.

In the mid-1980s, their experiments revealed how a current flowing through a superconducting circuit behaves as a single, collective quantum system. When trapped in a zero-voltage state, the system appeared unable to move – until, through tunnelling, it spontaneously escaped the barrier.

The detection of a voltage confirmed this transition and provided direct evidence of quantum behaviour in an engineered macroscopic system.

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“This is something that leads to development of the quantum computer. Many people are working on quantum computing, our discovery is in many ways the basis of this,” said Clarke.

While quantum mechanical effects are well established at the atomic and subatomic levels, they are typically invisible in everyday materials. The laureates’ research demonstrated that, under the right conditions, the quantum world can influence real-world electrical systems — a discovery that continues to shape the frontiers of computing and communications.

The Academy noted that “the transistors in computer microchips are one example of the established quantum technology that surrounds us.” It added that the laureates’ discoveries have opened “opportunities for developing the next generation of quantum technology, including quantum cryptography, quantum computers, and quantum sensors.”

As Professor Clarke reflected: “There is no advanced technology used today that does not rely on quantum mechanics, including mobile phones, cameras… and fibre optic cables.”