How does it work?

The latest version of the transmission electron microscope captures images of electrons in flight by hitting them with electron pulses lasting one quintillionth of a second. That’s a real feat, since electrons travel at about 2,200 kilometers per second, which allows them to orbit the Earth in just 18.4 seconds.

By using microscopes to examine tiny particles, researchers hope to understand the quantum physics behind the behavior and movement of electrons, and specifically how they fly. The results of the study were published on August 21.

This transmission electron microscope is similar to the very powerful camera in the latest versions of smartphones. It allows us to photograph things we couldn’t see before,
says lead author Mohammed Hassan, an associate professor of physics and optical sciences at the University of Arizona.

How electrons arrange and rearrange inside atoms and molecules is an important question in both physics and chemistry, but the fast nature of tiny particles makes them incredibly difficult to study.

In the early 2000s, physicists developed techniques for generating tiny attosecond pulses to create an exposure time that could capture the motion of electrons, a feat that earned the scientists the 2023 Nobel Prize in Physics.

But even a few attoseconds is too large to record individual electron movements. To achieve this, the physicists behind the new study He tuned the electron gun to produce pulses lasting only one attosecond.

These pulses hit the “sample” being examined, and when the electrons pass through it, they slow down, changing the shape of the wavefront of the electron beam. The slowed beam is magnified by a lens, and when the beam hits it, it hits a fluorescent material that glows.

By combining an electron pulse with two carefully synchronized light pulses (to excite electrons in the material and generate an electron pulse, respectively), scientists were able to probe the ultrafast motions of electrons inside atoms.

This is truly the first time in history that science has been able to observe electrons in action. Unfortunately, the scientists did not include photographs of this magnificent microscope in their paper.