"RRI Scientists Demonstrate Timing-Based Control Over Quantum Entanglement Decay"
Qubit
the fundamental unit of quantum information, capable of superposition of 0 and 1 simultaneously.
Quantum entanglement
a property linking two particles so that the state of one instantly determines the state of the other.
Quantum computing is a fundamentally different model of computation. Classical computers process information as binary bits, each bit is either 0 or 1. A qubit (quantum bit) can exist in both states simultaneously, a property called superposition. This allows quantum computers to explore many computational paths at once, making them potentially far more powerful than classical machines for specific problems such as cryptography, drug discovery, and materials simulation.
Entanglement is a second core quantum property. When two particles are entangled, the state of one is instantly correlated with the state of the other, regardless of the distance between them. This linkage is not just a curiosity, it is a practical resource. Quantum computers use entanglement to coordinate information across qubits, enabling computations that no classical system can replicate efficiently. Without sustained entanglement, a quantum computer loses its advantage.
India's institutional response to this technology is the National Quantum Mission (NQM), approved in 2023 with an outlay of ₹6,003 crore over eight years under the Department of Science and Technology (DST). The NQM targets quantum computers with 50–1,000 physical qubits, quantum communication networks, quantum sensing, and quantum materials. It envisages four Thematic Hubs (T-Hubs) anchored in academic and national R&D institutions. The Raman Research Institute (RRI), an autonomous institution under DST, is one of the key nodes in this ecosystem and is the institution behind the present research.
The central challenge in quantum computing is decoherence, the tendency of quantum systems to lose their quantum properties when they interact with the surrounding environment. Entanglement is particularly fragile. Even small disturbances, called noise, can cause the entanglement between two qubits to weaken and eventually vanish. In some cases, entanglement does not fade gradually. It disappears abruptly at a finite point in time, well before the underlying quantum states have fully decayed. Physicists call this entanglement sudden death (ESD).
ESD is a serious practical problem. If entanglement collapses before a computation is complete, the result is lost. Preventing or delaying ESD without redesigning hardware is therefore a high-value research goal. The standard approach to managing decoherence involves quantum error correction, which uses redundant qubits to detect and fix errors. However, error correction is resource-intensive and requires many additional physical qubits for each logical qubit protected. …
Which one of the following is the context in which the term "qubit" is mentioned?
Which one of the following is the context in which the term 'qubit' is mentioned?
Consider the following statements regarding the National Quantum Mission (NQM):
1.It was approved in 2023 under the Department of Science and Technology.
2.It targets quantum computers with 50–1,000 physical qubits.
3.It envisages setting up six Thematic Hubs (T-Hubs) in academic institutions.
4.Its total outlay is approximately ₹6,003 crore over eight years.
How many of the above statements are correct?
Match the following quantum computing terms with their correct descriptions:
List I (Term) — List II (Description)
A.Qubit — 1. Abrupt disappearance of entanglement at a finite time
B.Entanglement sudden death — 2. Loss of quantum properties due to environmental interaction
C.Decoherence — 3. Fundamental unit of quantum information exploiting superposition
D.Waveplate — 4. Optical device used to alter the polarisation of light
Choose the correct answer:
Consider the following statements regarding quantum entanglement and entanglement sudden death (ESD):
1.Entanglement sudden death refers to the gradual weakening of entanglement over a long period.
2.ESD can occur before the underlying quantum state has fully decayed.
3.The timing of a flip operation applied to an entangled system can determine whether ESD is avoided, delayed, or hastened.
Which of the statements given above is/are correct?
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