Quantum Computing: Single-Shot Control of Decoherence [Prelims Bits]

15 Sep 2026

Tags: Prelims   Current events of national and international importance

Source: The Indian Express

• Quantum Information and Computing (QuIC) Laboratory, Raman Research Institute (RRI), Bengaluru, demonstrated a single-shot operation to control quantum-state stability.
• The technique may improve reliability of quantum computations by delaying decoherence and avoiding entanglement sudden death.
• Classical bit: information encoded as 0 or 1.
• Qubit: quantum unit of information; can exist in a superposition of states.
• Superposition: quantum system can exist in multiple possible states simultaneously until measurement.
• Quantum entanglement: quantum correlation where measurement of one entangled particle provides information about the corresponding state of another, even when spatially separated.
• Decoherence: loss of quantum coherence due to interaction with the external environment, causing fragile quantum states to degrade.
• It undermines the integrity and reliability of quantum computation.
• Entanglement sudden death: abrupt disappearance of entanglement before its gradual natural decay.

RRI Breakthrough

• Developed a single-shot operation rather than repeated corrective interventions.
• Timing of the operation becomes a control parameter:
  • Appropriate timing → delays decoherence and can avoid entanglement sudden death.
  • Other timing → may accelerate decoherence.
• Demonstrated as a proof of concept, not a complete solution to decoherence or a replacement for quantum error correction.

Quantum Error Correction

• Conventional approach to combating decoherence involves repeated corrective operations.
• Such interventions can be costly and themselves introduce errors.
• The RRI approach potentially allows timing-based control alongside better materials, quantum gates and error-correction protocols.
• Raman Research Institute (RRI) is an autonomous research institute in Bengaluru, Karnataka, under the Department of Science and Technology (DST).
• Physical Review A is a peer-reviewed journal published by the American Physical Society (APS), covering atomic, molecular, optical and quantum physics.