Ideta S, Johnston S, Yoshida T, Tanaka K, Mori M, Anzai H, Ino A, Arita M, Namatame H, Taniguchi M, Ishida S, Takashima K, Kojima K M, Devereaux T P, Uchida S, Fujimori A
Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
UVSOR-III Synchrotron, Institute for Molecular Science, Okazaki 444-8585, Japan.
Phys Rev Lett. 2021 Nov 19;127(21):217004. doi: 10.1103/PhysRevLett.127.217004.
Hybridization of Bogoliubov quasiparticles (BQPs) between the CuO_{2} layers in the triple-layer cuprate high-temperature superconductor Bi_{2}Sr_{2}Cu_{2}Cu_{3}O_{10+δ} is studied by angle-resolved photoemission spectroscopy (ARPES). In the superconducting state, an anticrossing gap opens between the outer- and inner-BQP bands, which we attribute primarily to interlayer single-particle hopping with possible contributions from interlayer Cooper pairing. We find that the d-wave superconducting gap of both BQP bands smoothly develops with momentum without an abrupt jump in contrast to a previous ARPES study. Hybridization between the BQPs also gradually increases in going from the off nodal to the antinodal region, which is explained by the momentum dependence of the interlayer single-particle hopping. As possible mechanisms for the enhancement of the superconducting transition temperature, the hybridization between the BQPs as well as the combination of phonon modes of the triple CuO_{2} layers and spin fluctuations represented by a four-well model are discussed.
通过角分辨光电子能谱（ARPES）研究了三层铜酸盐高温超导体Bi₂Sr₂Cu₂Cu₃O₁₀₊δ中CuO₂层之间的博戈留波夫准粒子（BQP）的杂化。在超导状态下，在外层和内层BQP能带之间打开了一个反交叉能隙，我们主要将其归因于层间单粒子跳跃，并可能有层间库珀对的贡献。我们发现，与之前的ARPES研究相比，两个BQP能带的d波超导能隙随动量平滑发展，没有突然跳跃。从节点外区域到反节点区域，BQP之间的杂化也逐渐增加，这可以通过层间单粒子跳跃的动量依赖性来解释。作为提高超导转变温度的可能机制，讨论了BQP之间的杂化以及三层CuO₂层的声子模式与由四阱模型表示的自旋涨落的组合。
