2025 Nobel Prize in Physics Awarded for Groundbreaking Discovery in Quantum Mechanics

The 2025 Nobel Prize in Physics has been awarded to three scientists — John Clarke, Michel Devoret, and John Martinis — for their discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.

🔹 Key Question in Physics

A central question in modern physics has been:
👉 How large can a system be and still exhibit quantum mechanical effects?

• Tiny particles (microscopic), on the scale of atoms or smaller, behave in ways that are vastly different from the objects we encounter in daily life (macroscopic).
• These peculiar behaviours are explained by the laws of quantum mechanics.

🔹 Understanding Quantum Behaviour

• Superposition: Individual particles can appear to exist in multiple places simultaneously.
• Quantum Tunnelling: Particles can seemingly pass through solid barriers — a behaviour impossible under classical physics.
• Such effects are rarely observed in large objects, even though they are made up of the same small particles.

🔹 The Nobel Laureates’ Contribution

• The 2025 laureates conducted experiments with a superconducting electrical circuit large enough to be held in the hand.
• They demonstrated that even this macroscopic system could show quantum tunnelling — moving from one state to another as if passing straight through a wall.
• They also proved that the system absorbed and emitted energy in discrete, quantised amounts, precisely as predicted by quantum mechanics.

🔹 Significance of the Discovery

• The research bridges the gap between the microscopic quantum world and the macroscopic classical world.
• It opens new possibilities for quantum computing, quantum sensors, and the development of next-generation superconducting technologies.