Entangled Atomic Clocks

Table of Contents

Entangled Atomic Clocks- Relevance for UPSC Exam

General Studies III- Awareness in The Fields Of It, Space, Computers, Robotics, Nano-Technology, Bio-Technology, Pharma Sector & Health Science.

For the first time, scientists at the University of Oxford have been able to demonstrate a network of two entangled optical atomic clocks.

The high-precision atomic clocks and quantum entanglement have been achieved altogether.
This means the inherent uncertainty in measuring their frequencies simultaneously is highly reduced.

An atomic clock is a clock that uses the resonance frequencies of atoms as its resonator.
Cesium is incredibly accurate at timekeeping and is used in atomic clocks.

Entanglement is a quantum phenomenon in which two or more particles become linked together so that they can no longer be described independently, even at vast distances.
This is the key to reaching the fundamental limit of precision that’s determined by quantum theory.
Previous experiments have demonstrated that entanglement between two atomic clocks in the same system can be used to improve the quality of measurements.
This is the first-time researchers have been able to achieve this between clocks in two separate remotely entangled systems.

To determine a spacecraft’s distance from Earth, navigators send a signal to the spacecraft, which then returns it to Earth.
The time the signal requires to make that two-way journey reveals the spacecraft’s distance from Earth, because the signal travels at a known speed (the speed of light).
While it may sound complicated, most of us use this concept every day. The grocery store might be a 30-minute walk from your house.
If you know you can walk about a mile in 20 minutes, then you can calculate the distance to the store.
By sending multiple signals and taking many measurements over time, navigators can calculate a spacecraft’s trajectory: where it is and where it’s headed.

To know the spacecraft’s position within a meter, navigators’ need clocks with precision time resolution — clocks that can measure billionths of a second.
Navigators also need clocks that are extremely stable.
Stability refers to how consistently a clock measures a unit of time; its measurement of the length of a second, for example, needs to be the same (to better than a billionth of a second) over days and weeks.

Most modern clocks, from wristwatches to those used on satellites, keep time using a quartz crystal oscillator.
These devices take advantage of the fact that quartz crystals vibrate at a precise frequency when voltage is applied to them.
The vibrations of the crystal act like the pendulum of a grandfather clock, ticking off how much time has passed.

By space navigation standards, quartz crystal clocks aren’t very stable.
After only an hour, even the best-performing quartz oscillators can be off by a nanosecond (one billionth of a second).
After six weeks, they may be off by a full millisecond (one thousandth of a second), or a distance error of 185 miles (300 kilometers).
That would have a huge impact on measuring the position of a fast-moving spacecraft.
Atomic clocks combine a quartz crystal oscillator with an ensemble of atoms to achieve greater stability.