Antiferromagnetic spin fluctuations are the most promising candidate as the pairing glue of high critical temperature (Tc) superconductivity in cuprates. However, many-body states and intertwined orders have made it difficult to determine how electrons couple 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, using angle resolved photoemission spectroscopy and numerical simulations, we show a proportional relationship between Tc and the quasiparticle weight of the incipient hole pocket near the nodal point in electron-doped Pr_1−xLaCe_xCuO_4±δ. Through complementary muon spin spectroscopy measurements, we uncover that the hole pocket forms only in the regime of the fluctuating antiferromagnetic ground state around a presumed quantum critical point. Our observations highlight the significance of the electron-spin fluctuation interaction in enhancing the hole pocket and consequently driving superconductivity.

Authors: Dongjoon Song^#(서울대), Suheon Lee^#, Zecheng Shen, Woobin Jung, Wonjun Lee, Sungkyun Choi, Wonshik Kyung, Saegyeol Jung, Cheng-Maw Cheng, Junyoung Kwon, S. Ishida, Y. Yoshida, Seung Ryong Park, H. Eisaki, Yao Wang^*, Kwang-Yong Choi^* & C. Kim^* (서울대)

 

Publication date: 20 March 2025

DOI: https://doi.org/10.1038/s41467-025-57942-z