The 2025 Nobel Prize in Physics has been awarded to John Clarke, Michel H. Devoret, and John M. Martinis.
Their experiments gave us "the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.”
In 1984-85, the trio “demonstrated that quantum mechanical properties can be made concrete on a macroscopic scale.”
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 announcement was made by the Royal Swedish Academy of Sciences on Tuesday, 7 October 2025.
The Nobel Committee recognized the trio for their work in quantum mechanics. According to Olle Kämpe, chair of the committee, “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.”
In 1984-85, the trio conducted a series of experiments that “demonstrated that quantum mechanical properties can be made concrete on a macroscopic scale.” The team created a carefully measured electronic circuit built of superconductors separated by a thin insulating material. They measured, controlled, and explored phenomena that arose from passing a current through the circuit. They observed that “the charged particles moving through the superconductor comprised a system that behaved as if they were a single particle that filled the entire circuit.”
Initially the current flowed through the circuit without any voltage due to the non-conductive barrier, but the experiment showed a change in the system’s state, marked by the appearance of a voltage. The system was able to cross the 0V barrier – the physical barrier of the circuit – through a process called ‘tunnelling’.
In classical physics, mechanical laws state that an object cannot pass a barrier if it does not have sufficient energy to surmount it – think rolling a ball over a mound. The ball would need to have sufficient momentum to roll over the crest of the mound to the other side, otherwise it will roll back down the side it came.
Quantum tunnelling is a quantum mechanical phenomenon that allows particles to pass through an energy barrier even if it has lower energy than the barrier’s height. Tunnelling is possible due to the wave nature of particles, which gives them a non-zero probability of crossing the barrier. This probability decreases with increases in the particle’s mass, and the barrier’s height and width. As such tunnelling is observed primarily on quantum scales of matter.
The trio’s experiment proved that quantum properties could be exhibited on a macro-scale, much larger than anything previously observed. Further, they demonstrated that the system behaved in a predictable manner, in line with quantum mechanics.
This established the field of quantum technology, revolutionising modern machinery. The technology is now ubiquitous across fields, finding applications and explaining previously ununderstood phenomena in physics, biology, chemistry, atomic sciences, and, most relevantly, electronics.
Quantum tunnelling is the fundamental phenomenon underlying a number of electronic components and functions that have made scientific advancement and our modern lifestyles possible – used in TVs, satellites, computer chips, etc.
According to the Nobel Committee, “This year’s Nobel Prize in Physics has provided opportunities for developing the next generation of quantum technology, including quantum cryptography, quantum computers, and quantum sensors.”
John Clarke is a professor at the University of California, Berkeley. Michel H. Devoret is a professor at Yale University and the University of California, Santa Barbara. John M. Martinis is a professor at the University of California, Santa Barbara, and used to head Google’s Quantum Artificial Intelligence Lab.
The award will be conferred to the three later this year in December, along with three gold medals, and a million-dollar prize, which will be split evenly between them.
When contacted by the Nobel Committee, Clarke expressed his surprise. He had this to say: “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.”
This announcement is the second of ‘Nobel Week’, after the prize in Physiology or Medicine, which was announced on 6 October 2025. Winners for Chemistry, Literature, Peace, and Economic Sciences are to be declared over the coming days. The formal Nobel ceremony is scheduled to take place in Stockholm on 10 December 2025, the anniversary of Alfred Nobel’s death. [Rh/DS]