Emergent charge order in pressurized kagome superconductor CsV₃Sb₅

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity Research

Background:

• Kagome superconductors AV3Sb5 exhibit complex electronic orders, including charge density waves (CDW) and superconductivity.
• The interplay between CDW order and superconductivity under pressure is crucial for understanding emergent phenomena in these materials.
• Previous studies indicated time-reversal symmetry breaking and electronic nematicity within the triple-Q CDW phase.

Purpose of the Study:

• To investigate the pressure evolution of CDW order and superconductivity in CsV3Sb5.
• To elucidate the relationship between the newly discovered CDW phase and the observed two-dome superconducting behavior.
• To explore electronic correlation effects and superconducting pairing mechanisms under pressure.

Main Methods:

• Utilized 51V nuclear magnetic resonance (NMR) measurements to probe electronic properties.
• Performed nuclear spin-lattice relaxation measurements to investigate charge fluctuations and pairing.
• Analyzed the impact of applied pressure on CDW transitions and superconducting properties.

Main Results:

• Identified an emergent stripe-like CDW phase with a unidirectional 4a0 modulation between approximately 0.58 GPa and 2.0 GPa.
• This new CDW phase explains the previously observed two-dome-like superconducting behavior under pressure.
• Observed pressure-independent charge fluctuations above the CDW transition temperature and evidence for unconventional superconducting pairing above 2.0 GPa.

Conclusions:

• The study reveals a novel CDW phase in CsV3Sb5, significantly advancing the understanding of CDW-superconductivity interplay.
• The findings provide insights into unconventional superconducting pairing mechanisms and electronic correlations in kagome systems.
• This work offers a new perspective on emergent electronic orders and their influence on superconductivity in AV3Sb5 materials.