On October 7, 2025, the Royal Swedish Academy of Sciences awarded the Nobel Prize in Physics to three physicists whose work over four decades created the technical foundation for quantum computers: John Clarke, Michel H. Devoret, and John M. Martinis. The prize recognised their experimental demonstration of quantum mechanical effects in macroscopic electrical circuits — work that transformed quantum computing from a theoretical proposal into a physical reality.
The announcement was timely. In the same year it was awarded, quantum computers from IBM and Google were demonstrating practical advantages over classical machines for specific problems. The 2025 Nobel simultaneously honoured the past — the painstaking laboratory work that made quantum circuits possible — and signalled the present: the quantum era is no longer approaching. It has arrived.
This article explains the physics behind the prize, who the laureates are, why their work matters, and what comes next for quantum technology.
The Physics: Quantum Effects in Macroscopic Circuits
The central achievement recognised by the 2025 Nobel Prize is the experimental demonstration that quantum mechanical effects — including quantum tunnelling and energy quantisation — can be observed and controlled in electrical circuits large enough to be fabricated using standard semiconductor manufacturing techniques. This was not obvious, and its achievement required decades of careful experimental work.
Quantum mechanics governs the behaviour of matter at the atomic and subatomic scale. At larger scales, quantum effects are typically washed out by thermal fluctuations and interactions with the environment — the process called decoherence. The expectation was that circuits, being macroscopic objects containing trillions of atoms, would behave classically. Clarke, Devoret, and Martinis showed this expectation was wrong under the right conditions.
The key was the Josephson junction — a device consisting of two superconducting materials separated by a thin non-superconducting barrier. In superconductors, electrons form Cooper pairs that move through the material without resistance. When two superconductors are separated by a thin barrier, Cooper pairs can quantum tunnel through the barrier — a macroscopic quantum effect. The current that flows through a Josephson junction is governed by quantum mechanical equations, not classical ones.
By incorporating Josephson junctions into carefully designed circuits and cooling the entire system to temperatures near absolute zero — where thermal fluctuations are minimised and quantum coherence can be maintained — Clarke, Devoret, and Martinis demonstrated that individual circuits could be prepared in quantum superpositions, could be entangled with each other, and could be manipulated using precisely controlled microwave pulses. They had created qubits — quantum bits — from macroscopic electrical components.
This achievement is the physical foundation of every superconducting quantum computer built since. IBM’s quantum computers. Google’s Sycamore processor, which demonstrated quantum supremacy in 2019. The quantum processors now available through cloud platforms to researchers around the world. All of them use superconducting qubits built on the principles demonstrated by the 2025 Nobel laureates.
The Laureates
John Clarke is a British physicist who spent most of his career at the University of California, Berkeley, where he became one of the world’s leading experts on superconducting electronics. Clarke’s contributions to SQUID technology — Superconducting Quantum Interference Devices, extraordinarily sensitive detectors of magnetic fields based on the Josephson effect — laid crucial groundwork for the controlled manipulation of quantum states in circuits. SQUIDs are themselves quantum devices; Clarke’s decades of work on them built the experimental techniques and understanding that made qubit development possible.
Michel H. Devoret is a French-American physicist who has held appointments at CEA Saclay in France and Yale University in the United States. Devoret made foundational contributions to the theory and practice of quantum circuits, including the development of circuit quantum electrodynamics — the framework for understanding how superconducting qubits interact with microwave photons. This framework is the basis for reading out the state of superconducting qubits and for performing quantum gate operations between them.
John M. Martinis is an American physicist who worked at the National Institute of Standards and Technology before moving to the University of California, Santa Barbara, and subsequently to Google as a principal investigator in its quantum computing programme. Martinis’s group produced some of the most significant early demonstrations of high-fidelity quantum gate operations in superconducting qubits, and he led the team at Google that achieved the quantum supremacy demonstration in 2019 with the Sycamore processor.
The Road to the Prize: A Timeline of Key Milestones
The work recognised by the 2025 Nobel Prize spans four decades of incremental but decisive progress.
In the 1980s, Clarke and collaborators demonstrated the first clear evidence of macroscopic quantum tunnelling in Josephson junction circuits — showing that the magnetic flux trapped in a superconducting loop could tunnel between quantum states in exactly the way quantum mechanics predicted. This was the first demonstration that quantum mechanics applied to macroscopic circuit elements.
In the 1990s, Devoret and collaborators at CEA Saclay and Yale developed the theoretical framework of circuit quantum electrodynamics and demonstrated controlled quantum coherent oscillations in superconducting circuits — showing that circuits could be prepared in superpositions and that the superpositions could be maintained long enough to be observed and manipulated.
In the late 1990s and early 2000s, Martinis’s group at NIST and UCSB demonstrated increasingly high-fidelity quantum gate operations — the basic operations of quantum computing — in superconducting qubits, improving coherence times and gate fidelities to the point where multi-qubit computations became feasible.
In 2007, the transmon qubit — a design developed by Devoret’s group at Yale and colleagues — dramatically improved coherence times by reducing sensitivity to charge noise. The transmon is the basis for most superconducting qubits in use today, including those in IBM’s and Google’s quantum processors.
In 2019, Martinis’s team at Google demonstrated quantum supremacy with the Sycamore processor — the first credible claim that a quantum computer had performed a specific task faster than any classical computer could. The demonstration was contested in its details but marked a genuine milestone in quantum hardware development.
Why Superconducting Qubits Dominate Quantum Computing
Several physical platforms have been developed for quantum computing, including trapped ions, photonic systems, topological systems, and neutral atoms. Each has advantages and limitations. Superconducting qubits have emerged as the dominant platform for near-term large-scale quantum computing for several reasons rooted in the Nobel Prize-winning work.
Superconducting qubits can be fabricated using existing semiconductor manufacturing infrastructure — the same industry that builds classical computer chips. This means they can be produced at scale, integrated into complex circuits, and improved using the enormous engineering knowledge base of the chip industry. Other qubit technologies are harder to integrate at large scale.
Superconducting qubits are fast — quantum gate operations take nanoseconds, compared to microseconds for trapped-ion systems. This speed advantage means more computations can be completed within the coherence time of the qubit. And the microwave control techniques developed over decades of SQUID and Josephson junction research provide precise, reliable tools for manipulating qubit states.
The limitations — requiring cooling to millikelvin temperatures, sensitivity to electromagnetic noise, limited connectivity between distant qubits — are real and are the focus of ongoing engineering work. But the scalability advantages have made superconducting qubits the platform on which the most advanced quantum computers to date have been built.
For a detailed look at what IBM, Google, and Microsoft have achieved with their quantum systems and where they stand in 2026, see our article on quantum computing in 2026. For the fundamental physics of qubits and quantum advantage, see our article on the age of quantum computing: how close are we to practical quantum computers?
The Broader Legacy: Quantum Sensing and Quantum Communication
The impact of the 2025 Nobel Prize work extends beyond quantum computing. The quantum circuit techniques developed by Clarke, Devoret, and Martinis have applications in quantum sensing — the use of quantum systems to make measurements of extraordinary precision — and in quantum communication.
SQUIDs based on Clarke’s work are the most sensitive magnetic field detectors available, used in medical imaging systems, geophysical surveys, and fundamental physics experiments. Quantum-enhanced sensors using superconducting circuits are being developed for gravitational wave detection, dark matter searches, and precision measurements of fundamental constants.
The ability to produce and control individual microwave photons in circuit quantum electrodynamics systems — developed from Devoret’s theoretical framework — enables quantum communication at microwave frequencies, with potential applications in quantum networks connecting quantum computers.
The 2022 Nobel Prize in Physics, awarded to Alain Aspect, John Clauser, and Anton Zeilinger for their work on quantum entanglement and Bell inequality violations, and the 2025 Prize for quantum circuits together mark a remarkable period in which the Nobel committee has recognised the experimental foundations of quantum technology — the work that turned quantum mechanics from a theory into an engineering platform. For a deep dive into entanglement and the 2022 Nobel Prize work, see our article on quantum entanglement: the mystery at the heart of quantum mechanics.
Frequently Asked Questions
Who won the Nobel Prize in Physics 2025?
The 2025 Nobel Prize in Physics was awarded to John Clarke (UC Berkeley), Michel H. Devoret (Yale University), and John M. Martinis (UC Santa Barbara / Google) for their experimental demonstration of quantum mechanical effects in macroscopic electrical circuits — the foundational work that made superconducting quantum computers possible.
What is a Josephson junction?
A Josephson junction is a device consisting of two superconducting materials separated by a thin non-superconducting barrier. Cooper pairs of electrons can quantum tunnel through the barrier, producing a current governed by quantum mechanical equations. Josephson junctions are the key components of superconducting qubits.
What is a SQUID?
A SQUID — Superconducting Quantum Interference Device — is an extremely sensitive detector of magnetic fields based on quantum interference in a superconducting loop containing Josephson junctions. Developed primarily by John Clarke, SQUIDs are used in medical imaging, geophysical surveys, and fundamental physics experiments. They are among the most sensitive measurement devices ever created.
What is circuit quantum electrodynamics?
Circuit quantum electrodynamics (circuit QED) is the theoretical and experimental framework for understanding how superconducting qubits interact with microwave photons in electrical circuits. Developed by Michel Devoret and collaborators, it provides the basis for reading out qubit states and performing quantum gate operations in superconducting quantum computers.
What is the transmon qubit?
The transmon is a type of superconducting qubit developed by Devoret’s group at Yale in 2007, designed to reduce sensitivity to charge noise and dramatically improve coherence times. It is the basis for most superconducting qubits in use today, including those in IBM’s and Google’s quantum processors.
What did the Google quantum supremacy demonstration show?
In 2019, Google’s quantum team led by Martinis demonstrated that its Sycamore processor completed a specific random circuit sampling calculation in 200 seconds — a task Google claimed would take a classical supercomputer approximately 10,000 years. IBM contested the classical estimate, but the demonstration was widely recognised as a significant milestone in quantum hardware development.
Further Reading
- Nobel Prize in Physics 2025 — Official Summary
- Wikipedia — Josephson Effect
- Wikipedia — Superconducting Quantum Computing
- Wikipedia — Transmon Qubit
Sources
- Nobel Prize in Physics 2025 — Official Summary
- Wikipedia — Josephson Effect
- Wikipedia — Superconducting Quantum Computing
- Wikipedia — John Clarke
- Wikipedia — Michel Devoret
- Wikipedia — John Martinis
- Web News For Us — Quantum Computing in 2026
- Web News For Us — Quantum Entanglement
- Web News For Us — Practical Quantum Computers
About the Author
Baryon is the founder and editor of Web News For Us. Driven by a deep fascination with the biggest unanswered questions in science — from quantum physics and cosmology to the nature of consciousness and the genetic code written into every living cell — he has spent years studying modern physics, biology, and the history of scientific thought. He covers Science & AI, Space, Genetics & Research, and the timeless wisdom of history’s greatest thinkers and mystics.
If you have ever looked at the night sky and felt that pull to understand what is out there — or the wonder of an entire universe coiled inside your genes — you are in the right place.
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