Unconventional charge density wave in Kagome metal BaFe2Al9

Fuente: arXiv
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Autori principali: Chen, Liucheng, Ma, Mingwei, Yu, Xiaohui, Hong, Fang
Natura: Preprint
Pubblicazione: 2025
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author Chen, Liucheng
Ma, Mingwei
Yu, Xiaohui
Hong, Fang
author_facet Chen, Liucheng
Ma, Mingwei
Yu, Xiaohui
Hong, Fang
contents The charge density wave (CDW) is a macroscopic quantum state characterized by long-range lattice distortion and modulated charge density. Conventionally, CDWs compete with other electronic orders (e.g. superconductivity) and are suppressed under hydrostatic pressure. Intriguingly, the Kagome-variant metal BaFe2Al9, crystallized in a three-dimensional structure, exhibits pressure-enhanced CDW ordering, where the transition temperature (TCDW) rises from ~110 K to room temperature near 3.6 GPa. The lattice structure was checked by both powder and single crystal x-ray diffraction (XRD). The XRD data reveals an abnormal lattice expansion along a axis near 4-5 GPa upon compression. The strongly suppressed diffraction intensity and splitting diffraction spots from single crystal indicates cracking and breakdown to smaller pieces, indicative of an intrinsic first-order transition character. This anomalous response implies a CDW mechanism dominated by electron-electron and/or electron-phonon correlations, distinct from Fermi-surface nesting in conventional systems. Concomitant dome-shaped pressure-dependent resistance suggests competing electronic phases. Our work establishes BaFe2Al9 as a 3D Kagome platform with unconventional CDW behavior and strong electron-phonon coupling, which provides an alternative platform to explore the electron correlation induced exotic electronic states and other potential emergent quantum phenomenon.
format Preprint
id arxiv_https___arxiv_org_abs_2507_16325
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Unconventional charge density wave in Kagome metal BaFe2Al9
Chen, Liucheng
Ma, Mingwei
Yu, Xiaohui
Hong, Fang
Strongly Correlated Electrons
Materials Science
Superconductivity
The charge density wave (CDW) is a macroscopic quantum state characterized by long-range lattice distortion and modulated charge density. Conventionally, CDWs compete with other electronic orders (e.g. superconductivity) and are suppressed under hydrostatic pressure. Intriguingly, the Kagome-variant metal BaFe2Al9, crystallized in a three-dimensional structure, exhibits pressure-enhanced CDW ordering, where the transition temperature (TCDW) rises from ~110 K to room temperature near 3.6 GPa. The lattice structure was checked by both powder and single crystal x-ray diffraction (XRD). The XRD data reveals an abnormal lattice expansion along a axis near 4-5 GPa upon compression. The strongly suppressed diffraction intensity and splitting diffraction spots from single crystal indicates cracking and breakdown to smaller pieces, indicative of an intrinsic first-order transition character. This anomalous response implies a CDW mechanism dominated by electron-electron and/or electron-phonon correlations, distinct from Fermi-surface nesting in conventional systems. Concomitant dome-shaped pressure-dependent resistance suggests competing electronic phases. Our work establishes BaFe2Al9 as a 3D Kagome platform with unconventional CDW behavior and strong electron-phonon coupling, which provides an alternative platform to explore the electron correlation induced exotic electronic states and other potential emergent quantum phenomenon.
title Unconventional charge density wave in Kagome metal BaFe2Al9
topic Strongly Correlated Electrons
Materials Science
Superconductivity
url https://arxiv.org/abs/2507.16325