John Clarke, Michel H. Devoret, and John M. Martinis have been awarded the 2025 Nobel Prize in Physics for their pioneering experiments that made the strange phenomena of the quantum world visible on a macroscopic scale. Their work, conducted in the mid-1980s, confirmed some of the most counterintuitive predictions of quantum mechanics and laid the experimental groundwork for today’s rapidly advancing quantum technologies. By building a superconducting electrical circuit, they were able to observe a system “tunneling” through an energy barrier, a behavior previously only understood on the scale of individual particles.
The Royal Swedish Academy of Sciences in Stockholm announced the prize, recognizing the trio’s success in demonstrating that the bizarre properties of the quantum world can be realized in a system large enough to be held in the hand. This breakthrough has become a pillar of modern quantum engineering, underpinning the development of superconducting qubits, the building blocks of quantum computers. Their research not only provided a tangible demonstration of quantum mechanics in action but also opened the door to a new generation of technologies, including quantum cryptography, advanced sensors, and powerful new forms of computing. The prize, valued at 11 million Swedish kronor, will be shared equally among the three laureates.
Observing the Unseen World
The laureates’ award-winning research confronted two fundamental concepts of quantum mechanics: quantum tunneling and energy quantization. Quantum tunneling describes the ability of a particle to pass through a barrier that, according to classical physics, it should not have enough energy to overcome. Imagine a ball rolling up a hill; if it doesn’t have enough speed, it will roll back down. In the quantum realm, however, there is a finite probability that the ball could appear on the other side of the hill, as if it had tunneled straight through it. While this phenomenon was understood for individual particles, the work of Clarke, Devoret, and Martinis was a path-breaking demonstration of this effect on a much larger scale, involving many particles at once.
The second key concept is energy quantization, the idea that a system can only absorb or emit energy in discrete amounts, or “quanta.” The team was able to show that their superconducting circuit behaved precisely in this manner, absorbing and emitting specific amounts of energy as predicted by quantum theory. This was a crucial step in showing that the rules of quantum mechanics are not confined to the subatomic world but can be engineered into larger, more complex systems. “It is wonderful to be able to celebrate the way that century-old quantum mechanics continually offers new surprises,” said Olle Eriksson, Chair of the Nobel Committee for Physics.
A Groundbreaking Experiment
The seminal experiments were conducted in 1984 and 1985 at the University of California, Berkeley. At the time, Devoret was a postdoctoral fellow and Martinis was a graduate student in Clarke’s research group. Their innovative approach involved building an electrical circuit from superconducting materials, which can conduct electricity without any resistance at extremely low temperatures.
The Josephson Junction
At the heart of their device was a component called a Josephson junction. Named after Brian Josephson, who won the Nobel Prize for his theoretical work on the subject in 1973, this junction consists of two superconductors separated by a very thin layer of insulating material. This setup allows for the controlled observation of quantum effects. The wave functions describing the state of the system on either side of the junction interact, leading to the fascinating phenomena that the team was able to measure and control with unprecedented precision. They successfully refined their circuit to the point where they could measure all of its properties and understand it in detail, allowing for a clear demonstration of quantum tunneling on a macroscopic scale.
From Theory to Technology
The work of Clarke, Devoret, and Martinis has been instrumental in transforming quantum mechanics from a purely theoretical science into a practical field of engineering. Their experiments provided the foundation for what is now a global “quantum gold rush,” with nations and corporations investing heavily in the development of quantum technologies. The United Nations has even designated 2025 as the International Year of Quantum Science and Technology, underscoring the growing importance of the field.
Quantum Computing and Beyond
Perhaps the most significant application of their research is in the field of quantum computing. The superconducting circuits they pioneered are the basis for the “qubits” that are the fundamental units of information in a quantum computer. Unlike classical bits, which can be either a 0 or a 1, qubits can exist in a superposition of both states simultaneously, allowing quantum computers to solve problems that are intractable for even the most powerful supercomputers. The laureates’ work provided the engineering principles that are now used to build and control these delicate quantum systems. The implications extend beyond computing to include ultra-sensitive quantum sensors and secure communication methods based on quantum cryptography.
The Laureates and Their Legacy
The three scientists have continued to be leading figures in the field of quantum physics long after their initial collaboration. John Clarke, born in the U.K. in 1942, is a professor at the University of California, Berkeley, where the Nobel-winning research was conducted. Upon hearing of the prize, he expressed his surprise and paid tribute to the “overwhelming” contributions of his colleagues.
Michel H. Devoret, born in France in 1953, is a professor emeritus of applied physics at Yale University. He was a founding member of the Yale Quantum Institute and currently serves as the chief scientist for quantum hardware at Google Quantum AI. John M. Martinis, born in 1958, is a professor at the University of California, Santa Barbara. After a period working on quantum technology at Google, he co-founded the quantum computing startup Qolab in 2022.
A New Quantum Revolution
The recognition of their work some 40 years after the experiments were conducted highlights the long journey from fundamental discovery to technological application. What began as an effort to explore the esoteric rules of the subatomic world has now become the bedrock of a technological revolution. “This purely fundamental experimental research…is the pillar of today’s understanding and engineering of superconducting qubits that may very well make tomorrow’s quantum computers,” said physicist Arindam Ghosh.
The ability to create and manipulate quantum states in macroscopic systems has opened up a new frontier in physics and engineering. The work of Clarke, Devoret, and Martinis provided the crucial first step, demonstrating that the strange and powerful laws of quantum mechanics could be harnessed. As the world enters an era increasingly shaped by quantum technology, the legacy of their groundbreaking experiments will continue to grow, paving the way for innovations that were once the exclusive domain of science fiction.
