Evidence of a distinct collective mode in Kagome superconductors

Fuente: arXiv
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Main Authors: Hu, Bin, Chen, Hui, Ye, Yuhan, Huang, Zihao, Han, Xianghe, Zhao, Zhen, Xiao, Hongqin, Lin, Xiao, Yang, Haitao, Wang, Ziqiang, Gao, Hong-Jun
Format: Preprint
Published: 2024
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author Hu, Bin
Chen, Hui
Ye, Yuhan
Huang, Zihao
Han, Xianghe
Zhao, Zhen
Xiao, Hongqin
Lin, Xiao
Yang, Haitao
Wang, Ziqiang
Gao, Hong-Jun
author_facet Hu, Bin
Chen, Hui
Ye, Yuhan
Huang, Zihao
Han, Xianghe
Zhao, Zhen
Xiao, Hongqin
Lin, Xiao
Yang, Haitao
Wang, Ziqiang
Gao, Hong-Jun
contents The collective modes of the superconducting order parameter fluctuation can provide key insights into the nature of the superconductor. Recently, a family of superconductors has emerged in non-magnetic kagome material AV3Sb5 (A=K, Rb, Cs), exhibiting fertile emergent phenomenology. However, the collective behaviors of Cooper pairs have not been studied. Here, we report a distinct collective mode in CsV3-xTaxSb5 using scanning tunneling microscope/spectroscopy. The spectral line-shape is well-described by one isotropic and one anisotropic superconducting gap, and a bosonic mode due to electron-mode coupling. With increasing x, the two gaps move closer in energy, merge into two isotropic gaps of equal amplitude, and then increase synchronously. The mode energy decreases monotonically to well below 2Δ and survives even after the charge density wave order is suppressed. We propose the interpretation of this collective mode as Leggett mode between different superconducting components or the Bardasis-Schrieffer mode due to a subleading superconducting component.
format Preprint
id arxiv_https___arxiv_org_abs_2403_09395
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Evidence of a distinct collective mode in Kagome superconductors
Hu, Bin
Chen, Hui
Ye, Yuhan
Huang, Zihao
Han, Xianghe
Zhao, Zhen
Xiao, Hongqin
Lin, Xiao
Yang, Haitao
Wang, Ziqiang
Gao, Hong-Jun
Superconductivity
The collective modes of the superconducting order parameter fluctuation can provide key insights into the nature of the superconductor. Recently, a family of superconductors has emerged in non-magnetic kagome material AV3Sb5 (A=K, Rb, Cs), exhibiting fertile emergent phenomenology. However, the collective behaviors of Cooper pairs have not been studied. Here, we report a distinct collective mode in CsV3-xTaxSb5 using scanning tunneling microscope/spectroscopy. The spectral line-shape is well-described by one isotropic and one anisotropic superconducting gap, and a bosonic mode due to electron-mode coupling. With increasing x, the two gaps move closer in energy, merge into two isotropic gaps of equal amplitude, and then increase synchronously. The mode energy decreases monotonically to well below 2Δ and survives even after the charge density wave order is suppressed. We propose the interpretation of this collective mode as Leggett mode between different superconducting components or the Bardasis-Schrieffer mode due to a subleading superconducting component.
title Evidence of a distinct collective mode in Kagome superconductors
topic Superconductivity
url https://arxiv.org/abs/2403.09395