Wednesday 19 March 2025
High-pressure manipulation of a kagome lattice has revealed a cascade of Lifshitz transitions and an evolution in electronic structure, opening up new avenues for understanding these exotic materials.
Kagome lattices are characterized by triangular networks of atoms, which can give rise to unique properties such as flat-band ferromagnetism and unconventional charge density waves. These phenomena have been observed in various kagome materials, but the underlying mechanisms remain poorly understood.
Researchers at the Helmholtz-Zentrum Dresden- Rossendorf and other institutions have employed high-pressure infrared spectroscopy and pump-probe techniques to explore the properties of Fe3Sn2, a prototypical kagome metal. By compressing the material using a diamond anvil cell, they were able to modulate the breathing distortion of its kagome lattice.
The team found that as pressure increased, the electronic structure of Fe3Sn2 underwent a series of Lifshitz transitions, which are rare events in solids where the Fermi level crosses the bandgap. These transitions led to changes in the material’s optical conductivity and reflectivity, allowing researchers to infer the strength of electronic correlations.
The results suggest that the breathing distortion can be used as a control parameter for tuning the microscopic regime of kagome metals, potentially unlocking new properties and behaviors. The study also highlights the importance of high-pressure experiments in exploring the complex physics of these materials.
Further investigation using Raman spectroscopy revealed changes in the phonon modes of Fe3Sn2 under pressure, providing additional insight into the material’s lattice dynamics. The researchers found that the A1g mode, which is sensitive to the breathing distortion, was suppressed and eventually disappeared above a certain pressure threshold.
The findings have significant implications for our understanding of kagome lattices and their potential applications. By manipulating the breathing distortion, researchers may be able to design new materials with tailored electronic properties, such as improved superconductivity or magnetism.
The study demonstrates the power of high-pressure experimentation in uncovering the intricate physics of complex materials. As researchers continue to push the boundaries of pressure and temperature, they may uncover even more surprising phenomena that challenge our current understanding of these exotic systems.
Cite this article: “High-Pressure Manipulation Reveals New Electronic Structure in Kagome Metals”, The Science Archive, 2025.
Kagome Lattices, Lifshitz Transitions, High-Pressure Manipulation, Electronic Structure, Ferromagnetism, Charge Density Waves, Diamond Anvil Cell, Optical Conductivity, Phonon Modes, Raman Spectroscopy
