Presentation Information
[PC4-02-INV]Pressure-tuned superconducting state of CsV3Sb5 investigated via self-field critical current
Wenyan Wang1, Wei Zhang1, Lingfei Wang1, Xinyou Liu1, Jianyu Xie1, Siu Tung Lam1, Chun Wai Tsang1, Zheyu Wang1, Tsz Fung Poon1, Shanmin Wang2, Kwing To Lai1, Jeffery L. Tallon3, *Swee K. Goh1 (1. The Chinese University of Hong Kong (Hong Kong), 2. Southern University of Science and Technology (China), 3. Victoria University of Wellington (New Zealand))
Keywords:
kagome superconductors,high pressure,critical current
The kagome metal CsV3Sb5 features an interesting competition between the charge-density-wave (CDW) order and superconductivity. We have employed the self-field critical current (Ic,sf) to probe the superconducting state of CsV3Sb5 as a function of pressure [1,2]. Our measurements reveal that Ic,sf is dramatically enhanced on the border of the CDW order. Specifically, we observe a peak-like enhancement of Ic,sf at the zero-temperature limit centered at p* ~ 20 kbar, the same pressure at which the CDW phase transition vanishes (Figure 1). This provides strong evidence for a zero-temperature quantum anomaly in this class of pressure-tuned superconductor. Such a peak in Ic,sf resembles the findings in other well-established quantum-critical superconductors, hinting at the presence of enhanced quantum fluctuations associated with the CDW phase in CsV3Sb5. Leveraging the relationship between Ic,sf and the London penetration depth, we further investigate the superconducting pairing symmetry. Combining with the impurity effect, we show that our data, regardless of the presence of the CDW order, consistently support a nodeless superconducting gap.