Copenhagen, 7 October 2025 (dpa/MIA) - The Nobel Prize in Physics has been won by John Clarke, Michel H Devoret and John M Martinis "for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit," the Royal Swedish Academy of Sciences said.

All three scientists are affiliated with the University of California (UC), and Devoret also has a connection to Yale University. Devoret and Martinis are affiliated with UC Santa Barbara, north-west of Los Angeles, while Clarke works at UC Berkeley near San Francisco.

"Quantum mechanics allows a particle to move straight through a barrier, using a process called tunnelling," the academy said in a press release announcing the award on Tuesday.

A major question in physics is the maximum size of a system that can demonstrate quantum mechanical effects, the statement explained

This year's winners did experiments with an electrical circuit in which they "demonstrated both quantum mechanical tunnelling and quantised energy levels in a system big enough to be held in the hand," the statement said.

When large numbers of particles are involved, the effects of quantum mechanical usually become insignificant. The physicists' experiments showed "that quantum mechanical properties can be made concrete on a macroscopic scale."

"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.

Photo: epa