Trio Wins Physics Nobel for Breakthrough in Quantum Tunnelling

Why in the News ?

The 2025 Nobel Prize in Physics has been awarded to John Clarke, Michel Devoret, and John Martinis for their pioneering experiments that revealed deeper insights into the phenomenon of quantum tunnelling – a process where particles pass through barriers that would be impenetrable under classical physics.

Background

• Quantum mechanics, developed in the early 20th century, describes the behaviour of matter and energy at the atomic and subatomic levels.
• One of its strangest predictions is quantum tunnelling – where particles can cross energy barriers they classically should not.
• Earlier, such effects could be observed only indirectly.
• Over time, these principles formed the foundation for modern electronics, including transistors and semiconductors, which revolutionised computing.
• The Nobel-winning trio built on this legacy by demonstrating tunnelling experimentally through a controllable electrical device, thereby bridging the gap between abstract quantum theory and observable macroscopic systems.

Feature

• The scientists created an electrical circuit with two superconductors (materials that conduct electricity without resistance) separated by a thin non-conductive layer – known as a Josephson junction.
• In this setup:
  • Charged particles in the superconductors act collectively as a single “super particle.”
  • They demonstrated quantum tunnelling across the insulating barrier- a phenomenon where electrical flow occurs without applied voltage, defying classical expectations.
• The experiment allowed researchers to observe and control tunnelling effects in real-time, marking a major leap for quantum computing and nanoelectronics.

Challenge

• Quantum coherence: Maintaining the delicate quantum state for long enough to allow observation and computation remains a challenge.
• Environmental interference: Even minimal temperature changes or vibrations can disturb quantum states.
• Scaling: Translating such laboratory-scale quantum phenomena into reliable, scalable technologies like quantum computers requires enormous precision and error correction mechanisms.
• Cost and complexity: Superconducting circuits need ultra-low temperatures and sophisticated infrastructure.

Way Forward

• Continued innovation in superconducting qubits (the basis of quantum computers) could make quantum systems more stable and scalable.
• Cross-disciplinary collaboration – between physics, material science, and computer engineering – will be key to translating these principles into practical applications.
• Governments and private sectors are likely to expand funding in quantum technology ecosystems, much like how early semiconductor research birthed the digital age.
• Strengthening education and research infrastructure in quantum science will help developing nations, including India, participate in the next technological revolution.

Conclusion

The Nobel Prize to Clarke, Devoret, and Martinis underscores how quantum mechanics continues to surprise and transform technology even a century after its discovery.
By demonstrating quantum tunnelling in a tangible device, the trio not only deepened our understanding of the subatomic world but also opened doors to future breakthroughs in quantum computing, communication, and energy-efficient electronics – signalling that the “weirdness” of quantum physics is also its greatest strength.