The news and why it matters

The prize goes to John Clarke, Michel Devoret, and John Martinis for showing that whole electrical circuits can obey the rules of the quantum world. Using special superconducting devices, they built and tested circuits where particles tunnel through barriers and occupy discrete energy levels. Work that began in the 1980s now powers today’s superconducting quantum computers, ultra-sensitive sensors, and precision measurement tools.

What exactly they showed

• A real device, not just an idea: The laureates used two superconductors separated by a very thin insulating layer—a Josephson junction.
  
• Quantum tunnelling, scaled up: In such a junction, paired electrons can cross the barrier even when classical physics says they should not.
  
• Energy comes in steps: The circuits display quantised energy—only certain levels are allowed, like rungs on a ladder.
  
• Why this was a breakthrough: It proved that carefully designed macroscopic circuits can display pure quantum behaviour, making the lab-scale foundations for quantum bits, quantum sensors, and time-keeping.
  

Everyday picture: Think of a ball on one side of a low wall. In daily life the ball cannot cross without enough push. In the quantum world, a tiny chance exists that it appears on the other side. The laureates built circuits where this strange jump could be seen, measured, and controlled.

Why this shapes the present and the future

• Quantum computing: Superconducting circuits are the leading platform for quantum bits, which can explore many possibilities at once.
  
• Sensing and standards: These circuits enable ultra-sensitive magnetometers, low-noise amplifiers for astronomy, and precision measurements used in metrology.
  
• Science method: The work shows how prediction → careful device design → clean measurements can turn deep theory into usable technology.
  

India angle — policy, programmes, people

• National Quantum Mission (approved 2023): Long-term plan to build indigenous quantum computers, secure quantum communication, and high-precision sensing; funded at about six thousand crore rupees till 2031.
  
• Anusandhan National Research Foundation: Multi-year support for basic science and industry partnerships, crucial for patient, device-level research.
  
• National Supercomputing Mission and city science clusters: Strengthen the wider ecosystem—fabrication, cryogenics, control electronics, and skilled technicians.
  
• What to do now: invest in clean-room facilities, fabrication of superconducting devices, fellowships for device physicists and cryogenic engineers, and shared testbeds so students can build and measure real circuits.
  

Key terms

• Superconductivity: a state where a material carries electric current with no resistance when cooled.
  
• Josephson junction: two superconductors separated by a thin insulator that allows quantum tunnelling of paired electrons.
  
• Quantum tunnelling: particles cross a barrier they cannot cross in classical physics.
  
• Energy quantisation: systems can hold only specific energy values, not a smooth range.
  
• Quantum bit: a controllable quantum system used to process information in new ways.
  
• Ultra-sensitive magnetometer: a device that measures tiny magnetic fields, useful in geology, medicine and physics.
  

Exam hook

Key takeaways

• The prize recognises quantum behaviour in full electrical circuits: tunnelling and quantised energy made practical.
  
• This work underpins superconducting quantum computers and precision sensors.
  
• India’s National Quantum Mission and Anusandhan National Research Foundation can convert such science into home-grown devices and skills.
  

UPSC Mains (150 words)
“Explain how experiments on superconducting circuits established quantum tunnelling and energy quantisation at a macroscopic scale. Discuss their present uses in computing and sensing, and outline how India’s National Quantum Mission and research funding can build an indigenous device ecosystem.”

UPSC Prelims (MCQ)
Q. Which statements are correct?

1. A Josephson junction consists of two superconductors separated by a thin insulator.
   
2. Energy quantisation means a system may take only specific energy values.
   
3. The National Quantum Mission focuses only on satellite communication.
   Answer: 1 and 2 only.
   

One-line wrap
The laureates turned weird quantum rules into workable hardware—a clear path from deep theory to tools that India now aims to build at scale.