title: Quantitative determination of pairing interactions for high-temperature superconductivity in cuprates.
abstract: A profound problem in modern condensed matter physics is discovering and understanding the nature of fluctuations and their coupling to fermions in cuprates, which lead to high-temperature superconductivity and the invariably associated strange metal state. We report the quantitative determination of normal and pairing self-energies, made possible by laser-based angle-resolved photoemission measurements of unprecedented accuracy and stability. Through a precise inversion procedure, both the effective interactions in the attractive d-wave symmetry and the repulsive part in the full symmetry are determined. The latter is nearly angle-independent. Near T c, both interactions are nearly independent of frequency and have almost the same magnitude over the complete energy range of up to about 0.4 eV, except for a low-energy feature at around 50 meV that is present only in the repulsive part, which has less than 10% of the total spectral weight. Well below T c, they both change similarly, with superconductivity-induced features at low energies. Besides finding the pairing self-energy and the attractive interactions for the first time, these results expose the central paradox of the problem of high T c: how the same frequency-independent fluctuations can dominantly scatter at angles ±π/2 in the attractive channel to give d-wave pairing and lead to angle-independent repulsive scattering. The experimental results are compared with available theoretical calculations based on antiferromagnetic fluctuations, the Hubbard model, and quantum-critical fluctuations of the loop-current order.
authors.affiliation: Department of Physics and Institute for Basic Science Research, SungKyunKwan University, Suwon 440-746, Korea.; National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Bok
authors.affiliation: Department of Physics and Institute for Basic Science Research, SungKyunKwan University, Suwon 440-746, Korea.
authors.forename: Jong Ju
authors.initials: JJ
authors.lastname: Bae
authors.affiliation: Department of Physics and Institute for Basic Science Research, SungKyunKwan University, Suwon 440-746, Korea.; Asia Pacific Center for Theoretical Physics, Pohang 790-784, Korea.
authors.forename: Han-Yong
authors.identifier: 0000-0001-5424-5853
authors.initials: HY
authors.lastname: Choi
authors.affiliation: Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA.
authors.forename: Chandra M
authors.initials: CM
authors.lastname: Varma
authors.affiliation: National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.; Department of Physics and Astronomy, Shanghai JiaoTong University, Shanghai 200240, China.
authors.forename: Wentao
authors.initials: W
authors.lastname: Zhang
authors.affiliation: National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: He
authors.affiliation: National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yu
authors.affiliation: National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
authors.forename: X J
authors.initials: XJ
authors.lastname: Zhou
mesh_terms: D003300:Copper / Q000737:chemistry*; D006358:Hot Temperature
chemical_list: D003300:Copper
keywords: ARPES; Eliashberg functions; condensed matter physics; superconductivity