Physicists at MIT and their collaborators have made a fascinating breakthrough in the realm of quantum materials, leading to the discovery of a new method to create a state of matter known as a strange metal. This achievement holds significant promise due to the unique properties of strange metals, which deviate from those of conventional metals like copper and are particularly relevant in the study of high-temperature superconductors crucial for various applications.
The research, led by Joseph G. Checkelsky, an Associate Professor of Physics at MIT, and detailed in a paper published in Nature Physics with Linda Ye as the first author, unveils a novel approach to producing and investigating strange metals. This breakthrough not only sheds light on the behavior of these enigmatic materials but also opens doors to developing a comprehensive theory that elucidates their underlying principles. Such a theory has been elusive thus far but is critical for a deeper understanding of not only strange metals but also other materials, including high-temperature superconductors, which have immense technological potential.
The study builds upon prior work by Checkelsky and colleagues in 2018, where they delved into a class of quantum materials known as kagome metals. These materials feature a unique atomic arrangement resembling a Star of David or a sheriff's badge, which intrigued researchers due to its potential for hosting intriguing electron behaviors. The earlier research revealed the presence of Dirac fermions, nearly massless particles akin to light-carrying photons, within the kagome metal structure, marking a significant discovery at that time.
Building on this foundation, the physicists set out to explore further by investigating a phenomenon called a flat band within the kagome lattice. A flat band occurs when electrons essentially come to a standstill, allowing for intense interactions among them. This interaction is akin to calm seas turning into a tumultuous storm when electrons begin conversing with each other, resulting in the emergence of a strange metal state.
The significance of this discovery lies in the realization that the kagome lattice serves as a crucial design principle for generating new electronic states, with implications extending beyond strange metals. Linda Ye, now an assistant professor at the California Institute of Technology, reflects on the journey of this research, which began around 2015, emphasizing the incremental yet rewarding progress made over the years.
The collaborative effort involved researchers from MIT, Cornell University, Lawrence Berkeley National Laboratory, Harvard University, Vienna University of Technology, and the Leibniz Institute for Solid State and Materials Research. Their combined expertise and dedication culminated in unraveling the mysteries of quantum materials, paving the way for future advancements in condensed matter physics and materials science.
Source: Materials Research Laboratory, Massachusetts Institute of Technology