Enhanced Coupling of Superconductivity and Evolution of the Gap Structure in CsV3Sb5 via Ta Doping

Yiwen Li; Zhengyan Zhu; Qing Li; Yongze Ye; Zhiwei Wang; Yugui Yao; Hai Hu Wen

doi:10.1088/0256-307X/41/12/127301

Enhanced Coupling of Superconductivity and Evolution of the Gap Structure in CsV₃Sb₅ via Ta Doping

Yiwen Li
, Zhengyan Zhu
, Qing Li
, Yongze Ye
, Zhiwei Wang^*
, Yugui Yao
, Hai Hu Wen^*

^*Corresponding author for this work

School of Physics

Research output: Contribution to journal › Article › peer-review

Abstract

In this study, Kagome superconductors, i.e., CsV₃Sb₅ single crystals and its Ta-doped variant, Cs(V_0.86Ta_0.14)₃Sb₅, were studied in detail via specific heat measurements. Results revealed that the charge density wave (CDW) was suppressed and the superconducting transition temperature (T_c) considerably increased from 2.8 to 4.6 K upon Ta doping. The electronic specific heat of CsV₃Sb₅ was fitted with a model comprising an s-wave gap and a highly anisotropic extended s-wave gap, where 2Δ/k_BT_c was smaller than the weak coupling limit of 3.5. Cs(V_0.86Ta_0.14)₃Sb₅ exhibited two isotropic s-wave gaps and yielded a larger gap of 2Δ/k_BT_c = 5.04, indicating a significant enhancement in superconducting coupling. This evolution was attributed to the increased density of states near the Fermi level released by CDW gap suppression.

Original language	English
Article number	127301
Journal	Chinese Physics Letters
Volume	41
Issue number	12
DOIs	https://doi.org/10.1088/0256-307X/41/12/127301
Publication status	Published - 1 Jan 2025

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title = "Enhanced Coupling of Superconductivity and Evolution of the Gap Structure in CsV3Sb5 via Ta Doping",

abstract = "In this study, Kagome superconductors, i.e., CsV3Sb5 single crystals and its Ta-doped variant, Cs(V0.86Ta0.14)3Sb5, were studied in detail via specific heat measurements. Results revealed that the charge density wave (CDW) was suppressed and the superconducting transition temperature (Tc) considerably increased from 2.8 to 4.6 K upon Ta doping. The electronic specific heat of CsV3Sb5 was fitted with a model comprising an s-wave gap and a highly anisotropic extended s-wave gap, where 2Δ/kBTc was smaller than the weak coupling limit of 3.5. Cs(V0.86Ta0.14)3Sb5 exhibited two isotropic s-wave gaps and yielded a larger gap of 2Δ/kBTc = 5.04, indicating a significant enhancement in superconducting coupling. This evolution was attributed to the increased density of states near the Fermi level released by CDW gap suppression.",

author = "Yiwen Li and Zhengyan Zhu and Qing Li and Yongze Ye and Zhiwei Wang and Yugui Yao and Wen, \{Hai Hu\}",

note = "Publisher Copyright: {\textcopyright} 2024 Chinese Physical Society and IOP Publishing Ltd.",

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doi = "10.1088/0256-307X/41/12/127301",

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TY - JOUR

T1 - Enhanced Coupling of Superconductivity and Evolution of the Gap Structure in CsV3Sb5 via Ta Doping

AU - Li, Yiwen

AU - Zhu, Zhengyan

AU - Li, Qing

AU - Ye, Yongze

AU - Wang, Zhiwei

AU - Yao, Yugui

AU - Wen, Hai Hu

PY - 2025/1/1

Y1 - 2025/1/1

N2 - In this study, Kagome superconductors, i.e., CsV3Sb5 single crystals and its Ta-doped variant, Cs(V0.86Ta0.14)3Sb5, were studied in detail via specific heat measurements. Results revealed that the charge density wave (CDW) was suppressed and the superconducting transition temperature (Tc) considerably increased from 2.8 to 4.6 K upon Ta doping. The electronic specific heat of CsV3Sb5 was fitted with a model comprising an s-wave gap and a highly anisotropic extended s-wave gap, where 2Δ/kBTc was smaller than the weak coupling limit of 3.5. Cs(V0.86Ta0.14)3Sb5 exhibited two isotropic s-wave gaps and yielded a larger gap of 2Δ/kBTc = 5.04, indicating a significant enhancement in superconducting coupling. This evolution was attributed to the increased density of states near the Fermi level released by CDW gap suppression.

AB - In this study, Kagome superconductors, i.e., CsV3Sb5 single crystals and its Ta-doped variant, Cs(V0.86Ta0.14)3Sb5, were studied in detail via specific heat measurements. Results revealed that the charge density wave (CDW) was suppressed and the superconducting transition temperature (Tc) considerably increased from 2.8 to 4.6 K upon Ta doping. The electronic specific heat of CsV3Sb5 was fitted with a model comprising an s-wave gap and a highly anisotropic extended s-wave gap, where 2Δ/kBTc was smaller than the weak coupling limit of 3.5. Cs(V0.86Ta0.14)3Sb5 exhibited two isotropic s-wave gaps and yielded a larger gap of 2Δ/kBTc = 5.04, indicating a significant enhancement in superconducting coupling. This evolution was attributed to the increased density of states near the Fermi level released by CDW gap suppression.

UR - https://www.scopus.com/pages/publications/85214670076

U2 - 10.1088/0256-307X/41/12/127301

DO - 10.1088/0256-307X/41/12/127301

M3 - Article

AN - SCOPUS:85214670076

SN - 0256-307X

VL - 41

JO - Chinese Physics Letters

JF - Chinese Physics Letters

IS - 12

M1 - 127301

ER -

Enhanced Coupling of Superconductivity and Evolution of the Gap Structure in CsV₃Sb₅ via Ta Doping

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