• ●Quantum entanglement: a correlation that ties the state of one particle to another however far apart, so an operation on one affects the other; it is the core resource of quantum computing, communication and sensing.
• ●Entanglement sudden death: entanglement between a pair can vanish completely at a finite time, before the underlying decay of the excited state is finished - the phenomenon this study targeted.
• ●Decoherence: the loss of quantum behaviour as a system interacts with its environment, the basic limit on how long quantum information survives in a computer.
• ●Qubit: the quantum bit, the two-state unit of quantum information; here the two states were mimicked in an optical setup, with vertical polarisation as the excited state and horizontal as the ground state, controlled with a waveplate.
• ●The finding: whether a single flip operation hastens, delays or avoids sudden death depends entirely on WHEN in the decay it is applied - timing itself becomes a control resource.
• ●The experiment fitted neither of the two textbook noise models; the theorists found a tuning parameter that lets one setup represent both frameworks and everything in between.
• ●Raman Research Institute (RRI), Bengaluru: founded in 1948 by Sir C.V. Raman, an autonomous institute funded by the Department of Science and Technology since 1972; the study came from its Quantum Information and Computing (QuIC) lab led by Urbasi Sinha.
• ●National Quantum Mission: approved by the Union Cabinet on 19 April 2023 with an outlay of Rs 6,003.65 crore for 2023-24 to 2030-31, run by DST, targeting 50-1,000 physical qubit quantum computers in eight years across four verticals - computing, communication, sensing and metrology, and materials and devices - through four Thematic Hubs.

In quantum physics, what does the term 'entanglement sudden death' describe?