Scientists Discovered a Method to Prolong Quantum Entanglement

Syllabus: GS3/Science and Technology

Context

• Scientists at Raman Research Institute have demonstrated a novel way to increase the stability of the quantum states that enable computation in a quantum computer.

Quantum Computing

• Unlike traditional computers that encode electric states into 0s and 1s to store and process information, quantum computers make use of the properties of the quantum world to carry out calculations.
• Quantum Entanglement is a property of the quantum world in which two particles, after undergoing an interaction, get “linked” (or entangled) together in such a way that they begin to behave like one single system. 
  • Measuring certain properties of one reveals information about corresponding properties of the other, irrespective of the distance between the two.
• Scientists have used this property along with properties like superposition i.e. the ability of quantum particles to exist in multiple states at the same time, to build powerful quantum computers.

Challenges Faced by Quantum Computing

• The quantum states are themselves very fragile and ephemeral. 
  • The entangled state disintegrates very quickly on interaction with the external environment, a phenomenon known as decoherence. 
  • Sometimes, entanglement vanishes abruptly, too, even before the normal disintegration takes place known as entanglement sudden death.
• This weakness creates a problem for quantum computing and the integrity of the calculations becomes doubtful. 
• Scientists have tried to deal with this challenge by carrying out repeated corrective interventions that delay decoherence.
  • But these repetitive interventions are costly, and can introduce errors of their own.

Novel way to Increase the Stability of the Quantum States

• The scientists have developed a new technique that deals with decoherence in this context through a “single-shot operation.”
  • Depending on the instant when the operation is carried out, this operation can delay decoherence and entirely avoid sudden death.
  • They use a “flip operation” which gives scientists greater control over the different possibilities.

Significance

• Across quantum platforms, one of the central obstacles is decoherence, or the loss of a system’s quantum properties on interaction with the environment. 
• Scientists have not solved coherence but showed an important kind of noise called amplitude damping: the timing of one operation can change the fate of entanglement. 
• The work suggests that timing could become part of the control toolbox for quantum systems.

Source: IE