Physicists 'freeze' light for record-breaking minute

By Kristen Butler, UPI.com   |   July 26, 2013 at 12:37 PM

Light -- the fastest thing in the universe -- is exceedingly difficult to halt, and German researchers have managed to freeze light for a record-breaking one minute.

They also successfully stored and retrieved data in the experimental beam in the form of a 100-micrometer-long picture with three horizontal stripes on it -- a crucial step for quantum information processing.

Light travels about 300 million meters per second in a vacuum, and one minute is a very long time. In the one minute the light was stopped, it could have traveled about 11 million miles -- more than 20 round trips to the moon.

In 1999 scientists slowed light to just 17 meters per second, then in 2001 halted it completely for a fraction of a second. Earlier this year, researchers held light still for 16 seconds using cold atoms.

George Heinze and colleagues at the University of Darmstadt, Germany fired a laser at an opaque crystal. This sent the crystal's atoms into a quantum superposition of two states, making it transparent to a narrow range of frequencies -- a process called electromagnetically induced transparency (EIT).

Then, researches fired a second laser into the crystal, trapping it there by switching off the first laser, ending transparency and returning the crystal to its opaque state.

A magnetic field can extend storage time, but complicates laser configuration. To break the one-minute barrier, researchers created an algorithm to find the perfect magnet and laser combination.

Researchers say that with better materials, "there is clear hope that this could be a solid-state platform able to achieve coherent light storage for tens of minutes."

Related UPI Stories
Latest Headlines
Trending News
Test predicts teen risk factor for cardiovascular disease
Gene therapy effective against form of inherited vision loss
Foot of new human ancestor, Homo naledi, resembles our own
NASA releases thousands of Apollo mission photos on Flickr
Study: European austerity to blame for rise in male suicide