On October 7, 2025, the world of physics was abuzz with excitement as the Royal Swedish Academy of Sciences announced the Nobel Prize in Physics had been awarded to John Clarke, Michel H. Devoret, and John M. Martinis. Their groundbreaking experiments revealed that the bizarre laws of quantum mechanics, once thought to govern only the tiniest particles, could be demonstrated in electrical circuits large enough to see and hold—a finding that has reshaped the future of technology and our understanding of the universe itself.
The trio will share the 11 million Swedish kronor prize (about $1.2 million), a recognition not just of their scientific achievement, but of the profound impact their work has already had on digital communications and the burgeoning field of quantum computing. As Hans Ellegren of the Royal Swedish Academy of Sciences declared, the Nobel was awarded “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.” The experiments, carried out at the University of California, Berkeley in the 1980s, proved that superconducting circuits could act as a single quantum object—a revelation that laid the foundation for the superconducting qubits at the heart of today’s quantum computers.
For John Clarke, now an emeritus professor at UC Berkeley, the honor was wholly unexpected. “To put it mildly, it was the surprise of my life,” Clarke admitted during the announcement, echoing his astonishment to reporters and the Nobel committee alike. He was quick to credit his co-laureates: “I was in principle the leader of the group, of course, but their contributions are just overwhelming.” Michel H. Devoret, now at Yale University and UC Santa Barbara and chief scientist at Google Quantum AI, and John M. Martinis, at UC Santa Barbara and CTO of quantum computing start-up Qolab, were both essential to the breakthrough, Clarke emphasized.
Their pioneering work addressed a central mystery of quantum mechanics: could the strange behaviors seen in atoms and subatomic particles—like tunneling through barriers and existing in discrete energy states—be observed in much larger systems? Until their experiments, quantum effects were thought to disappear as the number of particles increased. But by constructing an electrical circuit known as a Josephson junction—where a thin insulating layer separates two superconductors—they demonstrated that billions of electrons could act in concert, moving as so-called Cooper pairs in a coordinated, wavelike fashion.
“The fact that you can see the quantum world in an electrical circuit in this very direct way was really the source of the prize,” said Irfan Siddiqi, chair of UC Berkeley’s Department of Physics and a former postdoctoral fellow in Devoret’s lab. The Josephson junction enabled the team to observe macroscopic quantum tunneling: the circuit, trapped in a zero-voltage state, could ‘tunnel’ through an energy barrier and emerge in a new state, just as quantum mechanics predicts. Even more remarkably, they showed that the system could only absorb or emit specific amounts of energy—quantized energy levels—like the discrete steps seen in atoms.
This experiment was, in essence, the birth of the superconducting qubit—the quantum bit that underpins today’s most promising quantum computers. “They showed that a macroscopic circuit kind of behaved like a single atom. It had levels,” Siddiqi explained. “That quantization of the energy levels is the source of all qubits. This was the grandfather of qubits.”
The Nobel committee’s summary noted, “Their research has opened the door to the next generation of quantum technologies, including quantum cryptography, computers and sensors—breakthroughs that will change how we do everything from discovering new drugs to stopping destructive cyberattacks.” Markus Reiher, a quantum chemist at ETH Zurich, marveled, “Wouldn’t it be amazing if quantum mechanics would play a more extensive role in chemistry, beyond that of electronic structure, photoexcitation, and proton tunneling?”
The award comes at a fitting moment: 2025 is the United Nations’ International Year of Quantum Science and Technology, and it marks the 100th anniversary of modern quantum mechanics. As Richard Fitzgerald, editor in chief of Physics Today, put it, the prize celebrates the journey “from understanding what’s going on in a single atom to today’s technology applications.” Göran Johansson, a member of the Nobel Committee for Physics, underscored the leap: “This really brings quantum physics from the subatomic world onto this chip,” he said, holding a quantum chip at the Stockholm announcement.
Quantum tunneling—the phenomenon at the heart of the laureates’ work—had long been observed in the atomic realm, such as in radioactive decay. But demonstrating it in a macroscopic system required extraordinary experimental care. The team’s Josephson junction acted as a quantum pendulum, with its energy levels and tunneling transitions meticulously measured and confirmed. Their success proved that quantum mechanics could govern the behavior of systems composed of billions of particles, not just individual atoms.
The practical implications are immense. Quantum computers, which use qubits to represent information in ways impossible for classical bits, promise to revolutionize fields from chemistry to cybersecurity. As UC President James B. Milliken noted, “Their research has opened the door to the next generation of quantum technologies, including quantum cryptography, computers and sensors.” Berkeley Chancellor Rich Lyons highlighted the university’s role in major quantum computing initiatives, including new quantum innovation zones recently established in California.
Clarke’s legacy extends beyond quantum tunneling. He is celebrated for inventing ultrasensitive detectors known as SQUIDs (superconducting quantum interference devices), used in everything from geophysics to biosensing and fundamental physics experiments. His low-noise quantum amplifiers, originally developed for the Axion Dark Matter Experiment, have become crucial tools for reading out quantum bits in quantum computers.
Born in Cambridge, UK, in 1942, Clarke has spent decades pushing the boundaries of low-temperature physics and quantum measurement. His accolades include the University of California’s Distinguished Teaching Award, the Fritz London Memorial Award, and the National Academy of Sciences Comstock Prize. Yet, by all accounts, he remains approachable and humble. Science communicator Ainissa Ramirez, who recently interviewed Devoret for a children’s book, described him as “one of those rare geniuses because he’s also very humble and approachable. You’re not going to understand what he’s explaining to you after five minutes but he still makes you feel like it’s possible for you to understand.”
As the Nobel committee noted, the 2025 prize honors not just a scientific achievement, but a transformation in how we understand and harness the quantum world. The laureates’ work has provided the building blocks for a new era of technology—one where the weirdness of quantum mechanics is no longer confined to theory or the atomic scale, but is now engineered onto chips and circuits, promising to reshape the world as we know it.
