Discovery of an intermediate nematic state in a bilayer kagome metal ScV6Sn6

Abstract Nematicity, spontaneous breaking of rotational symmetry, is a ubiquitous phenomenon in correlated quantum matter. Here we show a phase transition in high-quality ScV6Sn6 bilayer kagome metal at a temperature $${T}^{*}$$ T * , occurring seven Kelvins below the charge density wave transition...

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Bibliographic Details
Main Authors: Camron Farhang, William R. Meier, Weihang Lu, Jiangxu Li, Yudong Wu, Shirin Mozaffari, Richa P. Madhogaria, Yang Zhang, David Mandrus, Jing Xia
Format: Article
Language:English
Published: Nature Portfolio 2025-08-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-63294-5
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Summary:Abstract Nematicity, spontaneous breaking of rotational symmetry, is a ubiquitous phenomenon in correlated quantum matter. Here we show a phase transition in high-quality ScV6Sn6 bilayer kagome metal at a temperature $${T}^{*}$$ T * , occurring seven Kelvins below the charge density wave transition at $${T}_{{CDW}}$$ T C D W , as indicated by thermodynamic, transport, and optical measurements. This emerging intermediate phase does not exhibit spontaneous time-reversal-symmetry breaking, as evidenced by zero-field Sagnac interferometry. However, it displays a strong, spontaneous in-plane anisotropy between $${T}^{*}$$ T * and $${T}_{{CDW}}$$ T C D W , revealed by transport and optical polarization rotation measurements. A pronounced depolarization effect detected by the Sagnac interferometer further confirms its nematic nature. Unlike AV3Sb5, this phase, alongside the recently discovered intra-unit cell nematic order at lower temperatures, presents a diverse landscape of nematicities at multiple length and temperature scales. Our findings highlight ScV6Sn6 as a prime candidate for realizing symmetry-breaking phases driven by charge density competition, kagome physics, and Van Hove singularities.
ISSN:2041-1723