For more than a century, science has strived to demonstrate the diffraction of atoms, a major phenomenon for understanding matter at the atomic scale. This quest has tested the knowledge of physicists, but it is recently thanks to the astonishing properties of graphene, a revolutionary material, that this scientific frontier has been crossed.
Diffraction: a fundamental principle for understanding matter
The diffraction is a phenomenon where waves, whether light, electrons or atoms, propagate and interact with obstacles or regular networks. It was by observing this phenomenon that scientists were able to discover the wave properties of light and particles, leading to the formulation of wave-particle duality.
For decades, scientists successfully observed the diffraction of electrons, but the diffraction of atoms remained a mystery. Atoms, being much more massive and complex than electrons, were resistant to this phenomenon, which significantly delayed our abilities to study matter at its most basic scale. The idea of one day observing the diffraction of an atom through a crystal seemed very distant.
Graphene: a technological revelation
The breakthrough came thanks to graphenea form of carbon that consists of a single layer of atoms arranged in a hexagonal structure. This ultra-thin material, just one atom thick, has exceptional properties, including high stability, high conductivity and exceptional strength. These characteristics attracted the attention of scientists around the world, who quickly explored its applications in various fields, from electronics to nanotechnology.
It is precisely this exceptional atomic structure that allowed researchers to overcome a major obstacle in atomic diffraction. While high-energy atoms often damaged traditional crystals used for diffraction, graphene, with its thinness and strength, was able to withstand collisions with atoms without being destroyed. This is how a team of researchers led by Carina Kanitz at the University of Vienna managed to observe the diffraction of hydrogen and helium atoms through a graphene sheet.
The results of this experiment, published in July 2023, made it possible to validate a fundamental hypothesis: even atoms can exhibit wave-like behavior through crystals, provided that the experimental conditions are optimized, in particular the duration of interaction between the atoms and crystal.
The researchers observed diffraction patterns with up to eight reciprocal vectors of the grating, demonstrating the consistency and precision of the diffraction. The secret of this success lies in the short duration of the interaction between the atoms and the graphene. This short interaction prevents excessive energy transfer that could have damaged the crystal, allowing the atoms to diffract without causing material degradation.
Towards new frontiers in physics and nanotechnology
This breakthrough in atomic diffraction opens new perspectives in nanotechnology and the physics of materials. By better understanding the wave behaviors of atoms, scientists can not only refine theoretical models of matter, but also develop cutting-edge technologies for manipulating matter at the atomic scale. This could have a major impact on areas like creation of custom materialsl’atomic imaging and the quantum information storage.
The implications for quantum computers and the quantum physics are also vast. By observing atoms interacting with materials like graphene, it becomes possible to manipulate and control these atoms with unprecedented precision, which could make quantum computers more powerful and more accessible. Additionally, it could enable a better understanding of quantum phenomena such as intertwining and superposition, which are the basis of future technologies.
A preprint describing the experiment is available via arXiv and has not yet been peer-reviewed.
