A groundbreaking achievement has been made by an international team of researchers who successfully measured the electron spin within a class of quantum materials called “kagome materials.” The electron spin, which refers to the curvature of space in which electrons exist and move, was measured for the first time, leading to significant implications for the study of quantum materials. The research, published in Nature Physics, holds the potential to revolutionize various technological fields, including renewable energy, biomedicine, electronics, and quantum computing.
The research involved collaboration among scientists from the University of Bologna, CNR-IOM Trieste, Ca’ Foscari University of Venice, University of Milan, University of Würzburg (Germany), University of St. Andrews (UK), Boston College, and the University of Santa Barbara (U.S.). Domenico Di Sante, a professor at the Department of Physics and Astronomy “Augusto Righi” from the University of Bologna, participated in the study as part of his Marie Curie BITMAP research project.
By employing advanced experimental techniques and utilizing light generated by a particle accelerator called the Synchrotron, the researchers were able to directly measure electron spin in relation to the concept of topology. They harnessed modern methods for modeling matter’s behavior, allowing them to achieve this breakthrough measurement.
Di Sante likens the influence of specific shapes on topological properties to the example of a football and a doughnut. Just as the presence of a hole in a doughnut sets it apart from a football, electrons in materials exhibit different spinning behaviors based on certain quantum properties. This spinning behavior is analogous to how the presence of celestial bodies like stars, black holes, dark matter, and dark energy affects the trajectory of light in the universe, causing the bending of space and time.
Although the existence of electron spin has been known for many years, this study marks the first time it has been measured directly, particularly in terms of “topological spin.” The researchers employed a specific experimental technique called “circular dichroism,” which can only be used with a synchrotron source. Circular dichroism relies on the differential light absorption of materials based on their polarization.
The focus of the study was primarily on “kagome materials,” a class of quantum materials named after their resemblance to the interwoven bamboo threads of a traditional Japanese basket known as “kagome.” These materials have been instrumental in advancing our understanding of magnetic, topological, and superconducting properties. The findings from this research shed further light on the unique characteristics of kagome materials.
Di Sante emphasizes the importance of the collaboration between experimental and theoretical researchers in achieving these remarkable results. The theoretical researchers utilized sophisticated quantum simulations made possible by powerful supercomputers, guiding their experimental counterparts to the specific area of the material where the circular dichroism effect could be measured.
Source: Università di Bologna