A famous quantum effect can finally be predicted in real materials
Scientists have developed a powerful new way to calculate the Kondo effect, a strange quantum phenomenon that appears when magnetic atoms are embedded in metals. Instead of relying on simplified models, the method uses the real atomic and electronic structures of materials, allowing researchers to predict their behavior with far greater accuracy.
Key points
- Scientists at Caltech and Yale University have developed a method to precisely calculate the Kondo effect in specific real materials for the first time.
- The technique was tested on seven transition-metal atoms embedded in copper and was up to two orders of magnitude more accurate than conventional model-based predictions.
- The advance could support realistic computer simulations of complex quantum materials, including high-temperature superconductors.
Researchers at Caltech and Yale University have developed a way to precisely calculate the Kondo effect in specific real materials, a feat that had not previously been possible. The work is reported in a paper published in Science, with Linqing Peng (PhD '25) and Tianyu Zhu of Yale University as lead authors.
For decades, scientists relied on simplified models that captured the phenomenon only approximately. The new approach works directly from a material's true atomic and electronic structure, according to the article.
How the method works
The Kondo effect occurs when a single magnetic atom, such as iron or manganese, is placed as an impurity inside a metal such as copper. When the material is cooled below a temperature known as the Kondo temperature, its electrical resistance stops falling, reaches a minimum and then rises again.
Traditional approaches reduce a material's electronic structure to a small set of orbitals and use an approximate mathematical model. Chan and his colleagues instead adapted highly accurate computational tools from quantum chemistry, representing the magnetic impurities almost as if they were molecules while retaining the full complexity of their electronic interactions.
It is now possible to predict the properties of some complicated materials purely through computation without referring to experiment
— Garnet Chan
Results and outlook
The researchers tested their method on seven different transition-metal atoms embedded in copper. For most of the elements examined, the calculations were as much as two orders of magnitude more accurate than predictions from conventional model-based techniques.
Garnet Chan, Bren Professor of Chemistry at Caltech and senior author of the paper, said the first materials studied are like a prototype problem along the way to more complex phenomena such as high-temperature superconductors and quantum magnets. Peng said it is becoming realistic to predict material-specific behavior of correlated electrons from first principles.
