Uniaxial stress tuning of electronic superlattices in kagome metals

• Applicant: Professor Dr. Jochen Geck
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 571746356

Quantum materials featuring kagome layers have recently garnered significant attention as a platform where electronic correlations, reduced dimensionality, and geometric frustration converge, leading to very rich and interesting physics. In this project, we want to investigate materials with itinerant electrons on kagome lattices, focusing on the non-magnetic kagome metals AV3Sb5 (A = K, Rb, Cs) and ScV6Sn6. The first aim is to establish a unique multi-modal measurement approach that integrates x-ray diffraction, electrical resistivity, and stress-strain measurements into a single experimental setup. By combining this multi-modal method with angle-resolved photoemission spectroscopy, we will explore the structural and electronic properties of AV3Sb5 and ScV6Sn6 as a function of uniaxial compressive stress and temperature. At low uniaxial stress, our goal is to detwin the electronic superlattices in these materials, enabling us to resolve the ongoing debate about the atomic scale structure of the bulk electronic order. At higher stress levels up to 1.6 GPa we will search for new electronic instabilities, including potential nematic phases. Ultimately, this project aims to elucidate the mechanisms driving cooperative electronic states in non-magnetic kagome metals, with a particular emphasis on the role of electron-phonon coupling.

• DFG Programme: Research Grants