Physicists have developed the world’s fastest microscope, capable of capturing electrons in motion with unprecedented speed and precision.
This groundbreaking instrument, an advanced version of the transmission electron microscope, captures images of electrons in flight using electron pulses that last just one quintillionth of a second.
This achievement is remarkable because electrons travel at approximately 1,367 miles per second (2,200 kilometers per second), fast enough to circle the Earth in just 18.4 seconds.
The researchers aim to unlock new insights into electron behavior by using this ultra-fast microscope to study these tiny particles. Their findings were published on August 21 in the journal Science Advances.
"This transmission electron microscope is akin to the most advanced camera in a smartphone; it enables us to capture images of phenomena we couldn’t observe before, such as electron motion," said lead author Mohammed Hassan, an associate professor of physics and optical sciences at the University of Arizona, in a statement. "With this microscope, we hope the scientific community can deepen its understanding of the quantum physics governing electron behavior and movement."
Understanding how electrons arrange and rearrange themselves within atoms and molecules is a fundamental challenge in both physics and chemistry. However, the rapid nature of electrons makes them notoriously difficult to study.
To overcome this, physicists developed techniques in the early 2000s to generate attosecond pulses (1x10^-18 seconds), a breakthrough that earned the 2023 Nobel Prize in Physics. These ultra-short pulses allowed scientists to explore electron dynamics, including how they carry charge, behave in semiconductors and liquid water, and how chemical bonds between atoms break apart.
Yet, even attosecond pulses are insufficient to capture individual electron motions. To achieve this, the researchers in the new study refined an electron gun to produce pulses lasting just one attosecond.
These pulses strike the sample under investigation, causing the electrons to slow down and alter the shape of the electron beam’s wavefront. The slowed beam is then magnified by a lens and directed onto a fluorescent material, which emits light when struck by the beam.
By synchronizing the electron pulse with two carefully timed light pulses—one to excite the electrons in the material and another to assist in generating the electron pulse—the researchers were able to probe the ultrafast movements of electrons within atoms.
"We’ve achieved attosecond temporal resolution with our transmission electron microscope, which we’ve dubbed 'attomicroscopy,'" Hassan said. "For the first time, we can observe the intricate movements of electrons in real-time."
Sources:
Published 21 Aug 2024 in Science Advances; Attosecond electron microscopy and diffraction
Discover:
