Emergent superconducting fluctuations in a compressed kagome superconductor

Abstract

The recent discovery of superconductivity (SC) and charge density wave (CDW) in kagome metals AV3Sb5 (A = K, Rb, Cs) provides an ideal playground for the study of emergent electronic orders. Application of moderate pressure leads to a two-dome-shaped SC phase regime in CsV3Sb5 accompanied by the destabilizing of CDW phase; such unconventional evolution of SC may involve the pressure-induced formation of a new stripe-like CDW order resembling that in La-214 cuprate superconductors. Nonetheless, the nature of this pressure-tuned SC state and its interplay with the stripe order are yet to be explored. Here, we perform soft point-contact spectroscopy (SPCS) measurements in CsV3Sb5 to investigate the evolution of superconducting order parameter with pressure. Surprisingly, we find that the superconducting gap is significantly enhanced between the two SC domes, at which the zero-resistance temperature is suppressed and the transition is remarkably broadened. Moreover, the temperature dependence of the SC gap in this pressure range severely deviates from the conventional BCS behavior, evidencing for strong Cooper pair phase fluctuations. These findings reveal the complex intertwining of the stripe-like CDW with SC in the compressed CsV3Sb5, suggesting striking parallel to the cuprate superconductor La2-xBaxCuO4. Our results point to the essential role of charge degree of freedom in the development of intertwining electronic orders, thus provides new constraints for theories.

arXiv comment16 pages, 4 figures

References in corpus (31)

• A Common Thread: the pairing interaction for the unconventional superconductors
• Theory of Intertwined Orders in High Temperature Superconductors
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Discovery of unconventional chiral charge order in kagome superconductor KV3Sb5
• Roton pair density wave and unconventional strong-coupling superconductivity in a topological kagome metal
• Cascade of correlated electron states in a kagome superconductor CsV3Sb5
• Time-reversal symmetry-breaking charge order in a kagome superconductor
• Charge density waves and electronic properties of superconducting kagome metals
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Concurrence of anomalous Hall effect and charge density wave in a superconducting topological kagome metal
• The Physics of Pair Density Waves
• The Challenge of Unconventional Superconductivity
• Three-dimensional charge density wave and robust zero-bias conductance peak inside the superconducting vortex core of a kagome superconductor CsV${}_3$Sb${}_5$
• Andreev - Saint James reflections: a probe of cuprate superconductors
• Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal
• Two-Dimensional Superconducting Fluctuations in Stripe-Ordered La(1.875)Ba(0.125)CuO(4)
• Chiral flux phase in the Kagome superconductor AV${}_3$Sb${}_5$
• Stripe order in superconducting La(2-x)Ba(x)CuO(4) for 0.095 <= x <= 0.155
• Unconventional Superconductivity
• The Ground State of the Pseudogap in Cuprate Superconductors
• Probing multiband superconductivity by point-contact spectroscopy
• Intertwined vestigial order in quantum materials: nematicity and beyond
• s-wave superconductivity in kagome metal CsV${}_3$Sb${}_5$ revealed by ${}^{121/123}$Sb NQR and ${}^{51}$V NMR measurements
• Nodeless superconductivity in the kagome metal CsV${}_3$Sb${}_5$
• Directional point-contact Andreev-reflection spectroscopy of Fe-based superconductors: Fermi surface topology, gap symmetry, and electron-boson interaction
• Energy gaps in the failed high-Tc superconductor La1.875Ba0.125CuO4
• Pressure-induced dimensional crossover in a kagome superconductor
• Charge order, metallic behavior and superconductivity in La_{2-x}Ba_xCuO_4 with x=1/8
• Decoupled Pairing Amplitude and Electronic Coherence in Iron-Based Superconductors
• Continuous doping of a cuprate surface: new insights from in-situ ARPES
• Two types of charge order in the superconducting kagome material CsV${}_3$Sb${}_5$

Cited by in corpus (3)

• Pressure evolution of electron dynamics in the superconducting kagome metal CsV${}_3$Sb${}_5$
• Kagome materials $A$V${}_3$Sb${}_5$ ($A$=K,Rb,Cs): pairing symmetry and pressure-tuning studies
• Quantum dephasing of kagome superconductivity