TY - JOUR
T1 - A unique van Hove singularity in kagome superconductor CsV3-xTaxSb5 with enhanced superconductivity
AU - Luo, Yang
AU - Han, Yulei
AU - Liu, Jinjin
AU - Chen, Hui
AU - Huang, Zihao
AU - Huai, Linwei
AU - Li, Hongyu
AU - Wang, Bingqian
AU - Shen, Jianchang
AU - Ding, Shuhan
AU - Li, Zeyu
AU - Peng, Shuting
AU - Wei, Zhiyuan
AU - Miao, Yu
AU - Sun, Xiupeng
AU - Ou, Zhipeng
AU - Xiang, Ziji
AU - Hashimoto, Makoto
AU - Lu, Donghui
AU - Yao, Yugui
AU - Yang, Haitao
AU - Chen, Xianhui
AU - Gao, Hong Jun
AU - Qiao, Zhenhua
AU - Wang, Zhiwei
AU - He, Junfeng
N1 - Publisher Copyright:
© 2023, The Author(s).
PY - 2023/12
Y1 - 2023/12
N2 - Van Hove singularity (VHS) has been considered as a driving source for unconventional superconductivity. A VHS in two-dimensional (2D) materials consists of a saddle point connecting electron-like and hole-like bands. In a rare case, when a VHS appears at Fermi level, both electron-like and hole-like conduction can coexist, giving rise to an enhanced density of states as well as an attractive component of Coulomb interaction for unconventional electronic pairing. However, this van Hove scenario is often destroyed by an incorrect chemical potential or competing instabilities. Here, by using angle-resolved photoemission measurements, we report the observation of a VHS perfectly aligned with the Fermi level in a kagome superconductor CsV3-xTaxSb5 (x ~ 0.4), in which a record-high superconducting transition temperature is achieved among all the current variants of AV3Sb5 (A = Cs, Rb, K) at ambient pressure. Doping dependent measurements reveal the important role of van Hove scenario in boosting superconductivity, and spectroscopic-imaging scanning tunneling microscopy measurements indicate a distinct superconducting state in this system.
AB - Van Hove singularity (VHS) has been considered as a driving source for unconventional superconductivity. A VHS in two-dimensional (2D) materials consists of a saddle point connecting electron-like and hole-like bands. In a rare case, when a VHS appears at Fermi level, both electron-like and hole-like conduction can coexist, giving rise to an enhanced density of states as well as an attractive component of Coulomb interaction for unconventional electronic pairing. However, this van Hove scenario is often destroyed by an incorrect chemical potential or competing instabilities. Here, by using angle-resolved photoemission measurements, we report the observation of a VHS perfectly aligned with the Fermi level in a kagome superconductor CsV3-xTaxSb5 (x ~ 0.4), in which a record-high superconducting transition temperature is achieved among all the current variants of AV3Sb5 (A = Cs, Rb, K) at ambient pressure. Doping dependent measurements reveal the important role of van Hove scenario in boosting superconductivity, and spectroscopic-imaging scanning tunneling microscopy measurements indicate a distinct superconducting state in this system.
UR - http://www.scopus.com/inward/record.url?scp=85163690845&partnerID=8YFLogxK
U2 - 10.1038/s41467-023-39500-7
DO - 10.1038/s41467-023-39500-7
M3 - Article
C2 - 37369675
AN - SCOPUS:85163690845
SN - 2041-1723
VL - 14
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 3819
ER -