Nobel Prize in Physics 2025 awarded to John Clarke, Michel Devoret, and John Martinis for quantum tunnelling discovery

The 2025 Nobel Prize in Physics was awarded on Tuesday to John Clarke, Michel H. Devoret, and John M. Martinis for groundbreaking discoveries that revealed how quantum mechanics can govern the behaviour of electric circuits at a macroscopic scale.

The Royal Swedish Academy of Sciences said the trio was honoured “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit,” fundamental phenomena that helped bridge the gap between classical electronics and quantum physics.

The three scientists conducted pioneering experiments that demonstrated how quantum mechanical effects can manifest in a system large enough to be seen and held in the hand.

Their groundbreaking work in the mid-1980s used superconducting circuits, known as Josephson junctions, to reveal that quantum properties such as tunnelling and discrete energy levels could occur in a macroscopic electrical system.

“A major question in physics is the maximum size of a system that can demonstrate quantum mechanical effects. This year’s laureates showed that even large, engineered systems can exhibit quantum behaviour,” the Academy said in its citation.

In their experiments, Clarke, Devoret, and Martinis built a superconducting circuit separated by a thin non-conductive barrier. By precisely measuring and controlling the current through the circuit, they demonstrated that the system could escape a stable, zero-voltage state through quantum tunnelling.

They also showed that the system absorbed and emitted energy in discrete amounts, confirming that it behaved according to quantum mechanical principles.

“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,” says Olle Eriksson, Chair of the Nobel Committee for Physics.

The Nobel Prize in Physics has been awarded 119 times to 226 laureates between 1901 and 2025.

Last year, artificial intelligence pioneers John Hopfield and Geoffrey Hinton won the physics prize for helping create the building blocks of machine learning.