Nobel Prize in Physics 2025: John Clarke, Michel H Devoret, John M Martinis get award

John Clarke, Michel H Devoret and John M Martinis have received the Nobel Prize in Physics 2025 “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.” The Royal Swedish Academy of Sciences announced the winners today.

Clarke is a professor at University of California, Berkeley, US while Devoret works with Yale University, New Haven, CT and University of California, Santa Barbara. Martinis also serves as professor at the University of California, Santa Barbara.

“A major question in physics is the maximum size of a system that can demonstrate quantum mechanical effects. The 2025 physics laureates conducted 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,” said the official page of the Nobel Prize in a post on X.

Also read Nobel Prize in Medicine 2025 goes to Mary E Brunkow, Fred Ramsdell, Shimon Sakaguchi

In 1984 and 1985, the three researchers conducted a series of experiments with an electronic circuit built of superconductors. In the circuit, the superconducting components were separated by a thin layer of non-conductive material, known as a Josephson junction. By refining and measuring all the various properties of their circuit, they were able to control and explore the phenomena that arose when they passed a current through it. Together, the charged particles moving through the superconductor comprised a system that behaved as if they were a single particle that filled the entire circuit.

Nobel Prize 2025

“Their superconducting electrical system could tunnel from one state to another, as if it were passing straight through a wall. They also showed that the system absorbed and emitted energy in doses of specific sizes, just as predicted by quantum mechanics,” the academy added.

The chip holding the circuit in the experiment 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.