(STOCKHOLM – Oct 2025) In a landmark announcement made on October 7, the Royal Swedish Academy of Sciences conferred the 2025 Nobel Prize in Physics on three scientists for scientific discoveries which showcased quantum effects in electric circuits sized comfortably in the palm of the hand. Professors John Clarke, Michel H. Devoret, and John M. Martinis were awarded for their groundbreaking experiments which began in the 1980s and extended beyond, paving the way for bold exploration of phenomena which extended quantum mechanics beyond the atomic scale.
The results ultimately led to applications such as quantum computers and quantum sensing.
The Quantum Leap: Macroscopic Quantum Effects
Quantum mechanics has always been in tension with classical physics primarily due to the bizarre and strange predictions it makes electrons can “tunnel” through barriers, exist in superpositions, and behave as both a particle and wave. While these are relatively easy to observe at the smallest scales, most physicists would claim that quantum effects would fall off as systems grew larger. Clarke, Devoret, and Martinis’s work directly challenged that notion.
The work involved a superconducting circuit (an electric loop where current can be sustained without resistance) that was broken by a thin insulating, nonconductive layer made of a Josephson junction. By subjecting billions of electrons to these two conditions, the authors were able to demonstrate that quantum tunneling, and quantification of energy states happened to a macroscopic quantum system, sized comfortably in the palm of one’s hand.
The Experiments That Changed Physics
The key experiment of the laureates started with a simple question: How big does a system need to be for quantum effects to disappear? Over the next two years, their team designed and studied a custom-made superconducting circuit that incorporated a Josephson junction. When cooled to ultra-low temperatures, the circuit exhibited astonishing properties. All of the charge carriers acted together as a “macroscopic quantum particle”, originally confined to a zero-voltage energy state a “well” that could not be classically escaped.
When at a certain point, quantum tunneling took over: the collective state passed over the energy barrier, effectively moving the circuit into a higher-voltage state, which was recorded as a sudden measurable voltage present in their apparatus. Even more remarkable was the fact that energy levels were quantized; the system only absorbed and emitted discrete packets of energy, exactly as quantum mechanics describes for atoms and molecules.
“It is wonderful to be able to celebrate how quantum mechanics, over 100 years since its inception, can still surprise us,” stated Olle Eriksson, Chair of the Nobel Committee, in the official press release. “It is also extremely useful, as it forms the foundation for all digital technology.”
Transformative Implications: Quantum Technology and Beyond
This work is far more than a curiosity in physics — it represents the beginning of a technological revolution. The Nobel Prize citation of 2025 stated “this research has laid the foundations for superconducting quantum circuits, a key technology for today’s modern quantum computers.” Their circuits now form the basis for the fastest quantum processors on the planet, which are in turn powering research into artificial intelligence, cryptography, drug development, and climate prediction.
Quantum computers utilize tunneling, quantized energy levels, and superposition in order to perform calculations in ways that classical computers cannot even imagine. The experiments conducted by these laureates on macroscopic quantum particles directly set the stage to invent and engineer these exotic behaviors in larger, and eventually, practical devices. Today’s quantum computers are built around structures that are similar to superconducting circuits, and they are now moving towards solving optimized problems that cannot be scaled with conventional machines.
The reach goes deeper than even the quantum computers: Quantum sensors also built on the laureates’ principles, can detect faint magnetic fields, while mapping neural activity in the brain, and even help with navigation in deep space. Quantum cryptography, another technology at the forefront of research, uses quantum mechanics to develop networks that can offer ultra-secure communications.
The People Behind the Breakthrough
- John Clarke, a Professor at UC Berkeley, is known for his life’s work on superconducting quantum interference devices (SQUIDs), also powering numerous advanced detection systems today. The University of Cambridge noted Clarke for “pushing the door open for today’s quantum technology, putting theory into practice in real devices.”
- Michel H. Devoret holds positions at Yale and UC Santa Barbara. He has abundantly contributed to quantum measurement and control as well. His work on the field of “quantum engineering” has been a great inspiration to generations of physicists, driving innovations particularly in the field of quantum error correction, a central challenge in increasing the scale of quantum computers.
- John M. Martinis is also at University of California Santa Barbara, and is known for realizing quantum circuits moved from laboratory prototype to scalable devices. His influence in industrial and academic contexts has been critical in beginning to close the gap between basic science and applied – which is particularly relevant in the area of quantum computing.
When journalists reached Clarke after the announcement in Stockholm, he was “completely stunned,” mentioning that quantum tunneling “is now one of the reasons that cellphones work” – and “in a sense, our discovery forms the basis of quantum computing”.
A Centennial Celebration of Quantum Mechanics
This year’s Nobel Prize is coinciding with the one hundredth anniversary of quantum mechanics – a theory that has altered the rules for not just physicists, but technology and society overall. The award committee mentioned in their presentation; “quantum mechanics is now key to most of today’s transformative technologies, from supercomputers to smartphones.”
The Nobel recognition of Clarke, Devoret, and Martinis places emphasis on the evolving legacy of quantum mechanics. At the turn of the last century, quantum ideas perplexed and bewildered scientists; but today, we experience the tangible benefits of quantum in medicine, engineering, finance and communication.
Looking to the Future
The Nobel committee emphasized that the winners’ work “can lead to wholly new technologies,” and the competition for quantum advantage has just begun. Quantum computing powerhouses including Google, IBM, and current startups are continuously developing Clarke, Devoret, and Martinis’ ideas about initial experiments as they pursue their dream of error-corrected processors that can be scaled.
Physicists are simultaneously exploring how quantum effects can be used in various areas, from artificial intelligence to secure messaging to magnetic resonance imaging. Every new discovery builds on the work of the winners: quantum effects are not exclusively at a microscopic level. These quantum effects can be demonstrated, controlled, and engineered at normal size scales.
A New Era in Science and Technology
The recognition of John Clarke, Michel H. Devoret, and John M. Martinis with the Nobel Physics Prize 2025 reinforces a remarkable transition: quantum mechanics is no longer confined to the physicist’s chalkboards and atomic physics but instead permeates the circuits and technologies that define our time.
The demonstration of quantum tunneling and quantized energy levels in macroscopic circuits signifies a new era of quantum state manipulation that undoubtedly will be a springboard to a generation of quantum engineers and quantum innovators and scientists around the world.
As society opens the door to quantum technologies becoming part of everyone’s daily life, the potential of quantum images used for practical use and the challenge of utilizing quantum phenomena for practical use is due in great part to the work of these pioneers. The work of some of the most influential scientists of this era not only changed physics but is currently changing the world.
