Photo of single atom’s shadow taken for first time

By Grace Kim

An Australian research team has succeeded in photographing the shadow of a single atom for the first time, reported a science journal on June 3.

“We have reached the extreme limit of microscopy; you cannot see anything smaller than an atom using visible light,” said Prof. Dave Kielpinski of Griffith University’s Centre for Quantum Dynamics in Brisbane, Australia.

The Kielpinski/Streed research team worked for five years with a super high-resolution microscope that was able to concentrate images on a smaller area than had ever been achieved before, creating a darker image which was easier to see.

A single atom of the element ytterbium was trapped and exposed to a specific frequency of light. Under this light the atom’s shadow was cast onto a detector, and a digital camera was then able to capture the image.

Research team member Dr. Erik Streed said the photo has a myriad of implications, especially for biomicroscopy.

"Because we are able to predict how dark a single atom should be, as in how much light it should absorb in forming a shadow, we can measure if the microscope is achieving the maximum contrast allowed by physics,” he explained.

Dr. Streed expects high-resolution microscopes will allow scientists to observe processes within cells, under optimum microscropy conditions, without crossing the threshold and destroying them.