World's First Picture of the Shadow of a Single Atom
It takes a true photographer's patience to wait five years for the perfect shot. That's how long it took a team of scientists to snap a picture of an atom's shadow - the first ever photo of such a phenomenon.
At 1000 times smaller than a millimeter, the shadow may seem like just a blip, but this incredible feat could help physicists build a quantum computer, a machine capable of solving equations in just seconds that would take ordinary computers decades, reports The Australian.
"We have reached the extreme limit of microscopy; you can not see anything smaller than an atom using visible light," said Dave Kielpinski of Griffith University's Centre for Quantum Dynamics in Brisbane, Australia.
Like Us on Facebook
Using a high-precision laser, a sensor, and an ion trap - a kind of 'cage' that holds an atom in place within a vacuum by using electrical forces - the team was able to capture a single atom of ytterbium and exposed it to a specific frequency of light, producing its silhouette.
Most wavelengths of light would pass right by the atom without interacting with it, but the team found an incredibly specific wavelength that would be absorbed by ytterbium, and set out to make that atom cast a shadow in a way they could capture, reports MSNBC.
The photons - or particles of light - absorbed by the atom show in the image as the shadow that was cast onto the CCD detector. The light that travels around the atom shows as yellow and orange around the shadow. This is the smallest thing that can be seen in visible light.
"By using the ultra hi-res microscope we were able to concentrate the image down to a smaller area than has been achieved before, creating a darker image which is easier to see," Kielpinski said.
The team initially wanted to see how many atoms it would take to produce a shadow, and it turns out, it only takes one.
According to MSNBC, Kielpinski said they used ytterbium because "for many atomic elements, the correct lasers are very hard to build. The lasers we need to experiment on ytterbium ions are relatively simple and cheap. However, any atom would cast a shadow if you use the right color of laser."
Not only does this confirm our understanding of atomic physics, but it could be useful for looking at fragile biological specimens under the microscope.
"This is important if you want to look at very small and fragile biological samples such as DNA strands where exposure to too much UV light or x-rays will harm the material," said research team member Erik Streed. "We can now predict how much light is needed to observe processes within cells,under optimum microscopy conditions, without crossing the threshold and destroying them."
© 2012 iScience Times All rights reserved. Do not reproduce without permission.