Decades after his foundational experiments helped launch a new era in physics, Nobel laureate John Martinis is working to accelerate the development of quantum computers. The 67-year-old physicist, who shared the 2025 Nobel Prize in Physics for demonstrating macroscopic quantum effects, is now channeling his expertise into a private company, QoLab, with the goal of building practical quantum processors. Martinis, a professor at the University of California, Santa Barbara, has dedicated 40 years to the field and says he is driven by a “professional dream” to see quantum computing come to fruition.
Martinis’s recent Nobel honor recognizes a series of experiments he conducted in the mid-1980s as a doctoral student at the University of California, Berkeley, alongside his advisor John Clarke and postdoctoral researcher Michel Devoret. Their work proved that quantum phenomena, such as tunneling and energy quantization, could be observed in macroscopic, human-engineered circuits. This discovery was not only a profound demonstration of quantum mechanics at a larger scale but also laid the theoretical and experimental groundwork for the superconducting qubits that are at the heart of today’s most advanced quantum computing systems. His current focus is on overcoming the significant engineering hurdles that still prevent the construction of large-scale, fault-tolerant quantum computers.
Foundational Experiments in Quantum Mechanics
The research that earned Martinis and his colleagues the Nobel Prize involved the creation of a specialized electronic circuit known as a Josephson junction. This device, composed of superconducting materials separated by a thin insulating layer, allowed the researchers to observe and control quantum effects on a scale previously thought impossible. Prior to their work, quantum behaviors had primarily been observed in microscopic systems involving individual particles. The team’s experiments demonstrated that a collective system of billions of electrons could behave as a single quantum entity, a concept known as macroscopic quantum coherence.
Observing Macroscopic Quantum Tunneling
One of the key phenomena observed was macroscopic quantum tunneling. In classical physics, a particle cannot pass through a barrier if it does not have enough energy to overcome it. However, in the quantum world, particles have a probability of “tunneling” through such barriers. The experiments conducted by Martinis, Clarke, and Devoret in 1984 and 1985 showed that the phase difference across the Josephson junction, a macroscopic variable, could tunnel through an energy barrier. This was a landmark achievement that confirmed theoretical predictions and opened up new possibilities for manipulating quantum states in electronic circuits.
Demonstrating Energy Quantization
In addition to tunneling, the team’s work also provided a clear demonstration of energy quantization in a macroscopic system. They showed that the circuit would only absorb or emit energy in discrete amounts, or “quanta,” a hallmark of quantum mechanics. This was achieved by measuring the response of the Josephson junction to an applied current. These findings were crucial because they established that engineered superconducting circuits could be treated as artificial atoms, with controllable and well-defined quantum energy levels. This principle is the fundamental basis for the design of superconducting qubits.
The Quest for Quantum Supremacy at Google
Martinis’s foundational research led him to a prominent role in the burgeoning field of quantum computing. In 2014, Google hired Martinis and his research group from UC Santa Barbara to lead their effort in building a quantum computer. This partnership, known as the Google Quantum AI Lab, was a multi-million dollar initiative aimed at leveraging Martinis’s expertise in superconducting qubits. The goal was to build a quantum processor capable of performing a task that would be practically impossible for even the most powerful classical supercomputers, a milestone known as “quantum supremacy” or “quantum advantage.”
The culmination of this effort came in 2019 with the development of the Sycamore processor, a 53-qubit quantum chip. The Google team, led by Martinis, published a paper in the journal *Nature* detailing an experiment where Sycamore performed a specific computational task in 200 seconds. They estimated that the same task would have taken a state-of-the-art classical supercomputer approximately 10,000 years to complete. This was a landmark claim in the field of quantum computing, providing the first experimental evidence that a quantum device could outperform a classical one for a particular problem. While the practical utility of the specific task was limited, the achievement was a powerful demonstration of the potential of quantum computing and a significant step towards building more capable quantum machines.
A New Venture with QoLab
After leaving Google in 2020, Martinis co-founded QoLab in 2022 to continue his work on developing quantum computers. As Chief Technology Officer, he is guiding the company’s focus on what he believes is the key to building scalable and reliable quantum computers: advanced semiconductor manufacturing. Martinis has expressed a sense of urgency, stating that research and development in the U.S. needs to accelerate to realize the potential of quantum computing within our lifetimes. QoLab is collaborating with other startups and academic institutions involved in semiconductor production to advance the technology for quantum chips.
The company’s approach is based on the idea that the same fabrication techniques that have led to the exponential growth of classical computing, as described by Moore’s Law, can be adapted for quantum processors. By leveraging the precision and scalability of the semiconductor industry, QoLab aims to overcome some of the major challenges facing quantum computing, such as qubit coherence and error correction. This new chapter in Martinis’s career reflects his long-term commitment to the field and his belief in the transformative potential of quantum technology. The Development Bank of Japan has also announced its support for QoLab, intending to foster collaboration with Japanese research institutes and companies to establish Japan as a key manufacturing hub for superconducting quantum computers.
The Future of Quantum Computing
The work of Martinis and his fellow Nobel laureates has been instrumental in shaping the landscape of modern technology, from the digital devices we use every day to the cutting-edge research in quantum computing. The principles they demonstrated in their early experiments are now being applied in the development of quantum sensors, quantum cryptography, and, most notably, quantum computers. Companies like Google, IBM, and a growing number of startups are all pursuing the development of quantum computers based on the superconducting qubit technology that Martinis helped pioneer.
The potential applications of large-scale quantum computers are vast and could have a profound impact on numerous fields. These include the discovery of new drugs and materials through the simulation of molecular structures, the optimization of complex systems in finance and logistics, and the breaking of current encryption standards. However, significant challenges remain in building quantum computers that are large enough and reliable enough to solve these problems. Issues such as qubit stability, error correction, and the development of quantum algorithms are all active areas of research. Martinis’s ongoing work at QoLab represents one of the many efforts around the world to address these challenges and bring the promise of quantum computing closer to reality. His career, from his early, Nobel-winning discoveries to his leadership in both academia and industry, illustrates the long and collaborative journey of scientific and technological innovation.