The 2025 Nobel Prize in Physics: Quantum Tunnelling Beyond Theoretical Boundaries

On 8 October 2025, John Clarke, Michel Devoret, and John Martinis were awarded the Nobel Prize in Physics for something that would have seemed like science fiction a century ago: harnessing quantum mechanical tunnelling in electrical circuits. Their discovery broke the classical rules of physics by proving that electron pairs—caged at the quantum level—could "escape" through barriers in superconducting materials, generating measurable voltages. It is a coincidence too compelling to ignore that their achievement coincides with the UN-declared International Year of Quantum Science and Technology, celebrating a century of quantum mechanics since Werner Heisenberg first laid its groundwork in 1925.

But beyond the Nobel ceremony lies a question far more critical: What does this recognition signify for quantum technologies and their real-world applications?

A Leap Through Josephson Junctions

The physics behind their discovery lies at the heart of Josephson junctions—a device composed of two layers of superconducting material separated by an insulating barrier. These junctions enable electron pairs, called Cooper pairs, to 'tunnel' through the insulation, overcoming what classical physics considers an unbreachable gap. This phenomenon, aptly termed the Josephson effect, was previously understood only theoretically. Clarke, Devoret, and Martinis took it several steps further, demonstrating that such quantum tunnelling could be measured and harnessed in practical settings.

To grasp the novelty of this advancement, consider the fact that a Josephson junction operating under such quantum tunnelling conditions enables the following:

• Creation of superconducting qubits, the elementary units of a quantum computer.
• Quantum amplifiers, which amplify weak quantum signals with minimal noise—critical for scalable quantum systems.
• Precision voltage measurements, forming the globally accepted standard for the volt.

In short, this discovery is not mere experimentation—it provides the technological backbone for a rapidly maturing area of physics and engineering.

Applications and the Hype Around Quantum Technology

The intersection of quantum mechanics and technology is now one of the fastest-growing fields globally. India's recently launched ₹6,003 crore National Quantum Mission (2023-31) epitomizes this trend, aiming to develop indigenous quantum computing and communications technology by the decade's end. Josephson junctions find direct application here, forming the basis of superconducting qubits that India hopes to manufacture at scale. Yet, this hope demands some urgency: by 2024, global quantum computing funding already exceeded $35 billion, with massive government and corporate investments in countries like the United States and China.

Take the case of the United States, home to Martinis and Devoret. With the National Quantum Initiative Act (2018), the U.S. outlined a structured funding ecosystem, funnelling over $1.2 billion as of 2025 into quantum research centres, like Fermilab's quantum networking facility. Contrast this with India's current ecosystem, where funding remains fragmented and academic-industry collaboration is nascent. Without similar legislative backing and clearer long-term goals, the ₹6,003 crore allocation might remain aspirational rhetoric.

Institutional Weaknesses and Overlooked Trade-offs

Despite the immense promise of quantum technologies, there are pressing concerns. First, the sheer fragility of superconducting systems undermines scalability. Josephson junctions, while critical, require ultra-low temperatures—near absolute zero—achievable only in carefully controlled laboratory setups. Is it realistic, even in the next decade, for tech like this to leap from national laboratories to commercial sectors?

The second issue lies in intellectual capital. Countries like the U.S. heavily incentivize quantum research talent through dedicated visa programs and well-funded postdoctoral opportunities, pulling scientists from countries like India. For instance, Clarke’s innovations are rooted in work started in Britain but refined through institutions like UC Berkeley. In contrast, India faces a profound brain drain problem: how does one nurture quantum talent when institutions still struggle to offer competitive pay and infrastructure?

Lastly, the ethics of quantum amplifiers and surveillance-capable devices should not escape scrutiny. As quantum networks develop, privacy advocates have rightfully flagged concerns—is India even considering how such technologies might breach civil and digital liberties? The discourse on 'quantum ethics' remains suspiciously absent from policy documents.

Lessons from the Netherlands

For a concrete international comparison, look to the Netherlands. With its QuantumDelta NL program, the country outlined a €615 million plan aimed at building a fully functional quantum ecosystem by 2030. Unlike India, the Dutch government prioritized research collaborations with homegrown tech startups, while embedding ethical studies into university curriculums. Crucially, the program recognizes the infrastructural challenges of technologies like Josephson junctions and focuses on hybrid systems that combine classical and quantum computing. India’s National Quantum Mission, by comparison, risks overpromising without addressing the practical limitations of these superconducting technologies.

Pathways to Measurement and Success

What would constitute success in integrating discoveries like Clarke, Devoret, and Martinis’? First, India's quantum aspirations must align with realistic benchmarks. This includes tracking how many patentable superconducting technologies are developed domestically by the end of the decade. Second, there must be a focus on attracting and retaining international research talent through incentivized academic collaborations. No mission of this complexity can succeed in isolation.

At an operational level, metrics like the number of functioning superconducting qubits or whether precision quantum measurements (voltage, magnetic fields) have real-world industry adopters could act as key markers of success. Yet, whether these Nobel-winning phenomena can transcend the laboratory bubble remains an unanswered question—one India must address while crafting its own roadmap for quantum science.

Prelims Practice Questions

Practice Questions for UPSC

Prelims Practice Questions

Frequently Asked Questions