John Clarke, an emeritus professor of physics at the University of California, Berkeley, has been named a recipient of the 2025 Nobel Prize in Physics. Clarke shares the award with Michel H. Devoret and John M. Martinis, who were both affiliated with UC Santa Barbara during their research.
The Nobel committee recognized the trio “for the discovery of macroscopic quantum mechanical tunneling and energy quantization in an electric circuit.” Their work demonstrated that particles such as electrons can pass through barriers in ways not possible under classical physics, a phenomenon known as quantum tunneling. This effect was shown using a simple electrical circuit that included a superconductor.
During a call with the Nobel committee at their Stockholm press conference, Clarke expressed surprise at receiving the honor. “To put it mildly, it was the surprise of my life,” he said. That his work was Nobel Prize worthy “had not occurred to us in any way.”
Clarke acknowledged the contributions of his colleagues: “I was in principle the leader of the group, of course, but their contributions are just overwhelming.”
Building on this early research, Clarke developed a highly sensitive detector called a SQUID (superconducting quantum interference device). He has applied SQUIDs in various fields including geophysics, material evaluation, biosensing, and detecting NMR signals at very low frequencies.
Currently, Clarke is working with the Axion Dark Matter Experiment (ADMX), where he developed superconducting quantum amplifiers based on SQUID technology. These amplifiers have also been used to read out qubits for quantum computers.
Clarke is recognized as a Fellow of the Royal Society of London and an Honorary Fellow at Christ’s College, Cambridge. His previous honors include UC’s Distinguished Teaching Award and awards for scientific achievement such as the Fritz London Memorial Award and National Academy of Sciences Comstock Prize.
