Vladislav Pokorný, a physicist from the Institute of Physics of the Czech Academy of Sciences (FZU), is a co-author of a study that won the prestigious ACS Nano Impact Award 2026. In it, researchers managed to build a tiny memory by placing single molecules on the surface of a superconductor.
How small can computer memory get? Today's chips store each bit in structures made of thousands of atoms. An international team of physicists has now reached a remarkable result: they stored one bit of information in the position of a single electron inside a group of just four molecules.
The tip of a scanning tunnelling microscope can flip this position back and forth, switching the stored value between "0" and "1", without damaging the system. The work was carried out by chemists from Bern and experimental teams from Basel, together with theorists from Charles University and the Czech Academy of Sciences. The editors of ACS Nano ranked it among the most influential papers of the past year.
ACS Nano is one of the world's top journals in nanoscience. Each year, its editors give the ACS Nano Impact Award to only a few studies whose discoveries have moved the whole field forward the most.
What the research was about
The researchers worked with an organic molecule that carries one extra unpaired electron. Molecules like this are called radicals, and it is this unpaired electron that makes them act like a tiny magnet. The researchers placed them one by one onto the surface of a superconductor, a material that conducts electric current with no losses at all at low temperatures.
It is precisely the interplay between superconductivity and the magnetic moment of the molecules that often leads to interesting and non-trivial behaviour, the focus of a field called nanoscale superconductivity. To handle the individual molecules, the team used a scanning tunnelling microscope, whose very sharp tip moves across the surface with atomic precision and can both image the molecules and reposition them.
By slightly changing the position of the tip and the voltage on it, a molecule, or even a whole chain of molecules, can be switched between two states. The chain then works like one of the smallest memory cells imaginable, in which the stored zero or one corresponds to a tiny change in the position of a single electron.
Unlike earlier memory units, some of them even smaller (for example, an IBM team stored information in a single holmium atom), this one is highly stable. The information can be written repeatedly, and the cell holds its memory for a long time. That matters for its potential use in computing technologies.
The importance of the Czech theory
The measurements took place in laboratories in Switzerland. But Czech theorists played a key role in explaining the observed effects and in designing how the memory cell should look. Vladislav Pokorný from FZU of the Czech Academy of Sciences and Martin Žonda from the Faculty of Mathematics and Physics, Charles University, are members of a larger research group that has been working on nanoscale superconductivity for more than ten years. Drawing on their long experience, they built a model of how such a chain of molecules behaves and found a solution that reliably explained all the observed effects.
To get there, however, they first had to understand the properties of a single molecule. Then they studied a pair of molecules and systematically examined how the two influence each other. In the end, the theorists added to the experimental data a detailed picture of what happens at the level of individual electrons. In doing so, they revealed the processes that govern the interplay between superconductivity and the way electrons influence one another, both inside a single molecule and between the molecules in the chain.
Only then could the researchers understand the complex behaviour of the short chains and propose how to use them as memory cells. There is still a long way to go, however, before such molecular memories can be used in practice. Researchers must solve both how to transfer information between cells and a long-standing problem: how to connect such a molecular junction to classical electrodes, which are many orders of magnitude larger and would make it possible to link the cell to ordinary electronics.
Individual assembly of radical molecules on superconductors: Demonstrating quantum spin behavior and bistable charge rearrangement
C. Li, V. Pokorný, M. Žonda, J.-C. Liu, P. Zhou, O. Chahib, T. Glatzel, R. Häner, S. Decurtins, S.-X. Liu, R. Pawlak, E. Meyer, ACS Nano 19, 3403 (2025).