New superconductors can be built atom by atom
(Nanowerk News) What will the future computer look like? How does it work? The search for answers to these questions is a key driver of basic physics research. There are several possible scenarios, ranging from the further development of classical electronics to neuromorphic computing and quantum computers. The common element in all of these approaches is that they are based on novel physical effects, some of which have so far been predictable only in theory.
Researchers are pushing hard and using state-of-the-art equipment in their search for new quantum materials that would allow them to create such an effect. But what if there are no suitable ingredients that occur naturally?
A new approach to superconductivity
In a recent study published in Natural Physics (“Two-dimensional Shiba lattice as a possible platform for topological superconductivity of crystals”), the research group of UZH Professor Titus Neupert, in collaboration with physicists at the Max Planck Institute for Microstructural Physics in Halle (Germany), presented a possible solution. The researchers made the required materials themselves – one atom at a time. They focused on a new type of superconductor, which is very exciting because it offers zero electrical resistance at low temperatures.
Sometimes referred to as “ideal diamagnets,” superconductors are used in many quantum computers because of their extraordinary interactions with magnetic fields. Theoretical physicists have spent years researching and predicting various superconducting states.
“However, so far only small amounts have been conclusively demonstrated in the material,” said Professor Neupert.
Two new types of superconductivity
In their exciting 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 carried out experiments to implement the relevant topologies. Using a scanning tunneling microscope, they move and deposit atoms in the right places with atomic precision. The same method is also used to measure the magnetic and superconductive properties of the system.
By depositing chromium atoms on the surface of the superconducting niobium, the researchers were able to create two new types of superconductivity. Similar methods have previously been used to manipulate metal atoms and molecules, but until now it has never been possible to fabricate two-dimensional superconductors with this approach.
The results not only confirmed the theoretical predictions of the physicists, but also gave them reason to speculate about what new states of matter might be created in this way, and how they might be used in future quantum computers.
