Novel superconductors built atom by atom

Researchers at the University of Zurich have designed superconductors one atom at a time, thereby creating new states of matter. In a study published in Nature Physics, the research group of UZH Professor Titus Neupert, working with physicists at the Max Planck Institute of Microstructure Physics in Germany, developed a novel superconductor that offers zero electrical resistance at low temperatures.

Sometimes referred to as ‘ideal diamagnets’, superconductors are used in many quantum computers due to their extraordinary interactions with magnetic fields. Theoretical physicists have spent years researching and predicting various superconducting states; however, only a small number have been conclusively demonstrated in materials, according to Neupert.

In their collaboration, the UZH researchers predicted in theory how the atoms should be arranged to create a new superconductive phase, and the team in Germany then conducted experiments to implement the relevant technology. Using a scanning tunnelling microscope, they moved and deposited the atoms in the right place with atomic precision.

The same method was used to measure the system’s magnetic and superconductive properties. By depositing chromium atoms on the surface of superconducting niobium, the researchers were able to create two new types of superconductivity. Similar methods had previously been used to manipulate metal atoms and molecules, but two-dimensional superconductors had not been developed before, using this approach.

The research findings confirm the physicists’ theoretical predictions and give them reason to speculate about what other new states of matter might be created in this way, and how they could be used in quantum computers in the future.

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