Interplay between Hole Superconductivity and Quantum Critical Antiferromagnetic Fluctuations in Electron-Doped Cuprates

Abstract Antiferromagnetic spin fluctuations are the most promising candidate as the pairing glue of high critical temperature ( T c ) superconductivity. However, many-body states and intertwined orders in cuprates have made it difficult to determine how electrons interact with fluctuating spins to form Cooper pairs. Recent experimental and theoretical studies have suggested spin fluctuation-driven quasiparticle band folding, but the relationship between the resultant Fermi pockets and superconductivity remains unclear. Here, we investigated this relationship in electron-doped Pr 1−x LaCe x CuO 4±δ using angle-resolved photoemission and muon spin spectroscopy. By extracting the folded band component in the single-particle nodal band spectrum and analysing the muon relaxation rate, we discovered that T c is proportional to the quasiparticle weight of the nodal hole pocket in the regime of the fluctuating antiferromagnetic ground state around a presumed quantum critical point. Our experimental and numerical observations highlight the significance of the marked interplay between the electron correlation and antiferromagnetic fluctuations in enhancing the hole pocket and consequently driving superconductivity.