Revolution in microscopy: Göttingen researchers control electron beams!

Revolution in microscopy: Göttingen researchers control electron beams!

The ability to study the atomic structure and dynamics of matter is continually being improved by modern technologies. A groundbreaking example is the development of an attosecond electron microscope by Professor Peter Baum and his team at the University of Konstanz. This innovative device can visualize electrical oscillations of light and enables a deep understanding of the movements of atoms and electrons, which are crucial for material properties. The measurements over time periods of femtoseconds or even attoseconds – trillionths and billionths of a second – offer new insights into the behavior of matter based on the arrangement of atoms and electrons.

Previous measurement methods were limited in their effectiveness and could only record processes that were stimulated by high-energy laser pulses. The new development planned by Baum and his team, which is funded with an ERC Advanced Grant of 3.1 million euros, aims to overcome these limitations. The project will run for five years and is intended to create novel electron microscopes that can observe complete scenarios of electrically, magnetically or otherwise triggered processes. By using specifically generated sequences and spatial patterns of ultrashort electron pulses, the aim is to achieve a more comprehensive observation of atomic dynamics.

Technological advances in electron microscopy

A special challenge is to make microscopic structural changes visible on short time scales. The new ultrafast transmission electron microscope (UTEM) will play a key role in this research. It uses a “pump-touch” process with two time-delayed laser pulses. The first laser pulse excites the sample, while the second generates an electron pulse that maps the dynamics. This technology is unique in Germany and can revolutionize the previous methodology.

The UTEM will benefit greatly from the advances in time-resolved electron microscopy over the last few decades. Work has been underway to improve these technologies since the 1980s, and significant progress has been made by research teams around the world, such as in Göttingen, where new camera systems have been developed since 2010.

A new era of quantum mechanical measurement methods

In addition to advances in electron microscopy, researchers from Göttingen and Switzerland recently successfully manipulated an electron beam using an optical microchip system. These findings open up new possibilities for quantum mechanical measurement methods in electron microscopy. By using integrated photonics-based systems that can precisely direct light, interactions between free electrons and photons are improved. This allows the electron beam to pass through the optical near field of a photonic microresonator, resulting in significant changes in the energy of the electrons.

This allows electrons to absorb several hundred photons, expanding the applicability of electron beam manipulation in conventional electron microscopes. This combination of electron microscopy and photonics is of great importance for advances in fields such as materials science, structural biology and quantum computing, as it enables high-resolution imaging and spectroscopy.

Overall, it can be said that the shift in the limits of what can be measured through innovative technologies such as Baum's attosecond electron microscope and the UTEM as well as the combination with high-precision photonics is ushering in a new era of materials research in which the dynamic processes at the atomic level are becoming increasingly clear.