Physicists have been trying to observe the quantum phenomenon Kondo cloud for many decades. An international research team comprising a scientist from City University of Hong Kong (CityU) has recently developed a novel device that successfully measures the length of the Kondo cloud and even allows for controlling the Kondo cloud. The findings can be regarded as a milestone in condensed matter physics and may provide insights for understanding the multiple impurity systems, such as high-temperature superconductors.
Dr Ivan Valerievich Borzenets, Assistant Professor at CityU’s Department of Physics, collaborated with scientists from Germany, Japan, and Korea on achieving this breakthrough. Their research findings were published in the latest issue of the highly prestigious scientific journal Nature, titled “Observation of the Kondo Screening Cloud”.
The team spent almost three years in this research. Their next step is to investigate different ways to control the Kondo state. “Many other manipulations on the device can be done. For example, we can use two impurities at the same time and see how they will react when the clouds overlap. We hope the findings can provide insights into the understanding of multiple impurity systems such as Kondo lattices, spin glasses, and high transition-temperature superconductors.”
Dr Borzenets, Professor Sim Heung-Sun from Korea Advanced Institute of Science and Technology (KAIST) and Dr Michihisa Yamamoto of RIKEN Center for Emergent Matter Science (CEMS) in Japan are the corresponding authors of the paper. Dr Borzenets and Dr Shim Jeongmin from KAIST are the co-first authors. Other co-authors included Jason Chen C. H. from the University of Tokyo, Professor Dr Andreas D. Wieck and Dr Arne Ludwig from Ruhr-University Bochum, as well as Professor Seigo Tarucha from RIKEN CEMS.
The study was supported by CityU, Hong Kong Research Grants Council, Grants-in-Aid for Scientific Research (KAKENHI), Japan Science and Technology Agency and the National Research Foundation of Korea.
DOI number: 10.1038/s41586-020-2058-6
(More information about the research can be viewed from CityU Research Stories: https://bit.ly/2Uw9EwG)