Spectral Evidence for Unidirectional Charge Density Wave in Detwinned BaNi₂As₂

2022/05/28 by Yucheng Guo, Guo, Yucheng, Mason Klemm +35
Materials Science · #FOS: Physical sciences #Iron-based superconductors research #Strongly Correlated Electrons (cond-mat.str-el)

paper · pdf · doi:10.48550/arxiv.2205.14339

openalex publication_date 2022/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

The emergence of unconventional superconductivity in proximity to intertwined electronic orders is especially relevant in the case of iron-based superconductors. Such order consists of an electronic nematic order and a spin density wave in these systems. BaNi₂As₂, like its well-known iron-based analog BaFe₂As₂, also hosts a symmetry-breaking structural transition that is coupled to a unidirectional charge density wave (CDW), providing a novel platform to study intertwined orders. Here, through a systematic angle-resolved photoemission spectroscopy study combined with a detwinning B₁g uniaxial strain, we identify distinct spectral evidence of band evolution due to the structural transition as well as CDW-induced band folding. In contrast to the nematicity and spin density wave in BaFe₂As₂, the structural and CDW order parameters in BaNi₂As₂ are observed to be strongly coupled and do not separate in the presence of uniaxial strain. Our measurements point to a likely lattice origin of the CDW in BaNi₂As₂.

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