Light brought to a complete stop for one minute

Light brought to a complete stop for one minute

Scientists have brought the fastest thing in the universe - light - to a complete stop for a record-breaking minute.

A minute may not seem like much, but in just sixty seconds, light can travel an incredible distance of 18 million kilometres - enough time to orbit the Moon about 20 times.

"One minute is extremely, extremely long. This is indeed a major milestone," said Thomas Krauss at the University of St Andrews, UK.

While this is not the first time researchers have successfully stopped light, it is for the longest duration.

Physicists had managed to halt light completely in 2001, though only for a fraction of a second. Earlier this year, researchers kept it still for 16 seconds using cold atoms.George Heinze and colleagues at the University of Darmstadt, Germany, fired a control laser at an opaque crystal, sending its atoms into a quantum superposition of two states, 'New Scientist' reported.

This made it transparent to a narrow range of frequencies. Heinze's team then halted a second beam that entered the crystal by switching off the first laser and hence the transparency.

The storage time depends on the crystal's superposition. A magnetic field extends it but complicates the control laser configuration. Heinze's team used an algorithm to "breed" combinations of magnet and laser, leading them to one that trapped light for a minute.They also used the trap to store and then retrieve an image consisting of three stripes."We showed you can imprint complex information on your light beam," said Heinze.

Heinze said it should even be possible to stop light for longer periods of time with other crystals, but the current material has been pushed close to its physical limit.

The study was published in the journal Physical Review Letters. 

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