Enhancement of superconductivity and phase diagram of Ta-doped Kagome superconductor CsV3Sb5

Jinjin Liu; Qing Li; Yongkai Li; Xinwei Fan; Jun Li; Peng Zhu; Hanbin Deng; Jia-Xin Yin; Huaixin Yang; Jianqi Li; Hai-Hu Wen; Zhiwei Wang

doi:10.1038/s41598-024-59518-1

Enhancement of superconductivity and phase diagram of Ta-doped Kagome superconductor CsV₃Sb₅

Sci Rep. 2024 Apr 26;14(1):9580. doi: 10.1038/s41598-024-59518-1.

Authors

Jinjin Liu^{1

2}, Qing Li³, Yongkai Li^{1

2

4}, Xinwei Fan³, Jun Li⁵, Peng Zhu^{1

2

4}, Hanbin Deng⁶, Jia-Xin Yin⁶, Huaixin Yang⁷, Jianqi Li⁷, Hai-Hu Wen⁸, Zhiwei Wang^{9

10

11}

Affiliations

¹ Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
² Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
³ National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China.
⁴ Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314011, People's Republic of China.
⁵ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China. junli@iphy.ac.cn.
⁶ Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, People's Republic of China.
⁷ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
⁸ National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China. hhwen@nju.edu.cn.
⁹ Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China. zhiweiwang@bit.edu.cn.
¹⁰ Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China. zhiweiwang@bit.edu.cn.
¹¹ Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314011, People's Republic of China. zhiweiwang@bit.edu.cn.

Abstract

Kagome superconductors AV₃Sb₅ (A = K, Rb, and Cs) have attracted enormous interest due to the coexistence of charge density wave (CDW) order, unconventional superconductivity (SC) and anomalous Hall effect (AHE). In this paper, we reported an intensive investigation on Cs(V_1-xTa_x)₃Sb₅ single crystals with systematic Ta doping. Ta was confirmed to be doped into V-site in the Kagome layer from both single crystal X-ray diffraction structural refinement and scanning transmission electron microscopy observation. The highest Ta doping level was found to be about 16%, which is more than twice as much as 7% in Nb-doped CsV₃Sb₅. With the increase of Ta doping, CDW order was gradually suppressed and finally vanished when the doping level reached to more than 8%. Meanwhile, superconductivity was enhanced with a maximum critical temperature (Tc) of 5.3 K, which is the highest Tc in the bulk crystal of this Kagome system at ambient pressure so far. The μ₀H_c2(T) behavior demonstrates that the system is still a two-band superconductor after Ta doping. Based on the electrical transport measurement, a phase diagram was set up to exhibit the evolution of CDW and SC in the Cs(V_1-xTa_x)₃Sb₅ system. These findings pave a new way to search for new superconductors with higher Tc in the AV₃Sb₅ family and establish a new platform for tuning and controlling the multiple orders and superconducting states.

Abstract

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