Clarke, Devoret, and Martinis Awarded 2025 Nobel in Physics for Quantum Circuit Discovery

The 2025 Nobel Prize in Physics has been awarded 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.”

The laureates proved that quantum mechanical effects—like tunnelling and energy quantisation—can occur in systems large enough to be seen and handled, not just at the atomic level.

In 1984–85, John Clarke, Michel H. Devoret, and John M. Martinis conducted pioneering experiments using superconducting electronic circuits known as Josephson junctions.

The circuit used superconductors separated by a thin insulating layer, allowing current to flow without resistance and enabling precise control of quantum properties.

The system demonstrated quantum tunnelling, escaping from a zero-voltage state by “passing through” an energy barrier, something impossible under classical physics.

The researchers confirmed that the system absorbed and emitted energy in discrete (quantised) amounts, matching predictions of quantum mechanics.

The discovery showed that quantum behavior can manifest in macroscopic systems, bridging the gap between the quantum and classical worlds.

“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.