An experiment carried out by the University of Oxford researchers combines two unique and one can say even mind-boggling discoveries, namely, 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. The two-node network that they build is extendable to more nodes, the researchers write, in an article on this work published in Nature recently.
Atomic clocks grew in accuracy and became so dependable that in 1967, the definition of a second was revised to be the time taken by 9,19,26,31,770 oscillations of a cesium atom. At the start of the 21st century, the cesium clocks that were available were so accurate that they would gain or lose a second only once in about 20 million years. At present, even this record has been broken and there are “optical lattice clocks” that are so precise that they lose a second only once in 15 billion years. To give some perspective, that is more than the age of the universe, which is 13.8 billion years.
