Atomic mapping reveals diamond's secret power for future electronics
The University of Electro-Communications
image:
Spatial variations in dielectric constant arising from the unique electronic states of hydrogenated carbon surfaces.
view moreCredit: Jun Nakamura
From smartphones to medical sensors, modern electronics depend on materials' ability to store and manage electrical energy on an incredibly small scale. To make these devices smaller and more efficient, scientists must understand these properties at the atomic level. Researchers at the University of Electro-Communications have developed a pioneering method to create three-dimensional maps of a material’s dielectric response at the atomic level. Using this tool, they made a surprising discovery about diamond. Unlike most materials, such as silicon used in computer chips, which lose dielectric effectiveness at their surfaces, diamond actually shows an increase. This "anomalous enhancement" is caused by unique electrons on the diamond's surface. These electrons behave as if they are floating, making them highly responsive to electrical fields. This discovery provides a blueprint for the next generation of carbon-based technology. It could lead to the development of "cold cathodes," which are highly efficient electron sources that operate at low voltages, as well as smaller, faster electronic components. Harnessing these surface effects could enable us to create more powerful, energy-efficient gadgets that remain cool despite their smaller size.
Journal
ACS Omega
Method of Research
News article
Subject of Research
Not applicable
Article Title
Method for Evaluating the Spatial Distribution of Dielectric Constants: Application to hydrogenated C(111) and Si(111) surfaces
Zooming in: Electron orbitals photographed in 3D
Physicists at Göttingen University image three-dimensional wavefunctions with table-top, soft-X-ray laser
University of Göttingen
image:
An illustration of how researchers used state-of-the-art photoelectron spectroscopy (left hand side) with a lab-based soft-X-ray light source that provides ultrashort light pulses, which was combined with powerful mathematical algorithms, to image the wavefunction of electron orbitals (right-hand side).
view moreCredit: Lukas Kroll
One of the most famous and intriguing results of quantum mechanics is the finding that fundamental particles, such as electrons, cannot be pinned down to one single location. Instead, a particle is described by its “wavefunction”, which allows researchers to derive probability distributions – a sort of mathematical map that shows the possibilities – of fundamental properties such as its position and momentum. In particular, the electron wavefunctions within a molecule, known as “molecular orbitals”, carry information about how the molecule interacts with its surroundings. For example, it shows how it may absorb light or how a chemical reaction might take place. As a consequence, knowledge of the complete three-dimensional wavefunction is highly desirable, but imaging the wavefunction has proven to be a major experimental challenge. An interdisciplinary research team at the University of Göttingen has now managed to image the three-dimensional wavefunction of a nanometer-sized organic molecule. They overcame the limitations by combining state-of-the-art photoelectron spectroscopy with powerful mathematical algorithms. The results were published in Nature Communications.
“The wavefunction is a fundamental quantity in quantum mechanics, yet it cannot be directly observed or measured,” explains Professor Stefan Mathias at the University of Göttingen. Instead, the team relied on an indirect approach: namely, photoelectron spectroscopy, where the momentum of the emitted electrons is measured to provide access to one half of the wavefunction, without physically altering its state. Sophisticated computer algorithms then deduced the other half, allowing researchers to image the complete molecular orbital and to resolve features that are smaller than the distance between the carbon atoms that make up the molecule. However, applying this principle in 3D previously required time-intensive measurements at large-scale synchrotron facilities, limiting its widespread application and, in particular, its extension towards imaging “dynamical” wavefunctions in a 3D video at the scale of an atom.
Dr Matthijs Jansen, University of Göttingen, and co-leader of the study, highlights the originality of the team’s approach: “We introduce two powerful new concepts. First, by redesigning the computer algorithm from the ground up, reliable 3D images can now be obtained using much less experimental data. Second, the experiment is based upon a powerful, lab-based soft-X-ray light source that provides ultrashort light pulses. It is the combination of these two techniques that has this remarkable impact.” Dr Wiebke Bennecke, first author of the study, adds: “This technique might mean that stroboscopic videography becomes a reality, allowing us to observe not just the shape of wavefunctions, but also to see how it changes with ultrafast, even femtosecond or one quadrillionth of a second, resolution. This will mean we can learn how a molecule adapts to optical, electronic, or chemical changes and find new ways to control these interactions at the level of a few atoms.”
Original publication: Bennecke, W. et al. "Table-top three-dimensional photoemission orbital tomography with a femtosecond extreme ultraviolet light source." Nature Communications (2026). DoI: 10.1038/s41467-026-74308-1
Journal
Nature Communications
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Table-top three-dimensional photoemission orbital tomography with a femtosecond extreme ultraviolet light source.
One of the 3D wavefunction photographs, here showing the highest-occupied molecular orbital of PTCDA, a molecule that is often used for the fabrication of red dyes due to the strong interaction with light. In the centre, a 3D representation is shown, while the side panels show slices through the orbital at 1 Å (one ten-billionth of a meter) away from the centre of the molecule.
Credit
Reproduced from Bennecke, W. et al. Nature Communications (2026), published under a CC 4.0 licence.
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