A new record breaking imaging technique, powerful enough to watch individual atoms vibrate

Image of psychographically reconstructed Praseodynium orthoscandate (PrScO₃) crystals

A new technique, that's powerful enough to spot individual atoms in three-dimensional space and form a record resolution image.

This study was published in the Science Journal, on an electron microscope coupled with 3D reconstruction algorithms, and researchers even say that this might be as good as it gets.

This team led by David Muller, Samuel B. Eckert Professor of engineering has set a new record, beating the old record which was their own, by a  factor of two with an Electron Microscope Pixel Array Detector (EMPAD), and the results are so stunning that the only blurring that remains is due to the thermal jiggling of atoms.

Muller said, “This doesn’t just set a new record. It’s reached a regime that is effectively going to be an ultimate limit for resolution. We basically can now figure out where the atoms are in a very easy way. This opens up a whole lot of new measurement possibilities of things we’ve wanted to do for a very long time."`

“We’re chasing speckle patterns that look a lot like those laser-pointer patterns that cats are equally fascinated by. By seeing how the pattern changes, we can compute the shape of the object that caused the pattern.”

The detector is slightly defocused, which blurs the beam to get the widest range of data possible, which is then reconstructed with algorithms, resulting in a very precise image with picometer precision, which is just crazy.

“With these new algorithms, we’re now able to correct for all the blurring of our microscope to the point that the largest blurring factor we have left is the fact that the atoms themselves are wobbling because that’s what happens to atoms at finite temperature,” Muller said. “When we talk about temperature, what we’re actually measuring is the average speed of how much the atoms are jiggling.”

They can also, possibly beat their record again by using a material that consists of heavier atoms, which wobble less, or by cooling down the sample. This latest form of ptychography will enable scientists to locate individual atoms in a three-dimensional space, and also be able to find impurities in unusual configurations. This could be helpful in imaging semiconductors, catalysts, and quantum materials, analyzing atoms where materials are joined together.

In 2018, they could only take images of very thin samples, just a few atoms thick, but due to this new technique, they will be able to work on thicker materials, the imaging could also be applied on thick biological cells or tissues or synapse connections in the brain. 

Refernce: DOI: 10.1126/science.abg2533