Why in News:

• An experiment carried out by the University of Oxford researchers combined  high-precision atomic clocks and quantum entanglement, to achieve two atomic clocks that are “entangled.” This means the inherent uncertainty in measuring their frequencies simultaneously is highly reduced.
• While this is a proof-of-concept experiment, it has the potential for use in probing dark matter, precision geodesy and other such applications

Atomic clocks

• Atomic clock, a type of clock that uses certain resonance frequencies of atoms (usually cesium or rubidium) to keep time with extreme accuracy.
• Atomic clocks are designed to measure the precise length of a second, the base unit of modern timekeeping.
• The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. This definition refers to a caesium atom at rest at a temperature of 0 Kelvin.
• In an atomic clock, the natural oscillations of atoms act like the pendulum in a grandfather clock. However, atomic clocks are far more precise than conventional clocks because atomic oscillations have a much higher frequency and are much more stable.
• The more mundane uses to which these clocks can be put include accurate time keeping in GPS, or monitoring stuff remotely on Mars.

What is quantum entanglement

• Quantum entanglement is a bizarre, counterintuitive phenomenon that explains how two subatomic particles can be intimately linked to each other even if separated by billions of light-years of space. Despite their vast separation, a change induced in one will affect the other.
• When we look at particles, we usually say that each particle has its own quantum state. Sometimes, two particles can act on one another and become an entangled system. When a pair or group of particles can only be described by the quantum state of the system, and not by individual quantum states, we say the particles are “entangled”.
• Entanglement between particles happens because little particles can push and pull on each other, just like big objects do in terms of gravity.

Read about Quantum cryptography- https://officerspulse.com/quantum-cryptography/

Mains Question: What are some of the recent developments in the field of quantum technologies– https://bit.ly/3qKAt0A

References:

1. https://www.thehindu.com/sci-tech/using-spooky-action-at-a-distance-to-link-atomic-clocks/article65900639.ece
2. https://www.nasa.gov/vision/earth/technologies/23jan_entangled.html
3. https://www.nasa.gov/feature/jpl/what-is-an-atomic-clock
4. https://www.britannica.com/technology/atomic-clock