Evolution from a charge-ordered insulator to a high-temperature superconductor in Bi2Sr2(Ca,Dy)Cu2O8+δ

作者：Changwei Zou, Jaewon Choi, Qizhi Li, Shusen Ye, Chaohui Yin, Mirian García‐Fernández, Stefano Agrestini, Qingzheng Qiu, Xinqiang Cai, Qian Xiao, Xingjiang Zhou, Ke‐Jin Zhou, Yayu Wang, Y. Y. Peng · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-52124-9 · 被引用次数：6 · 研究领域：Physics of Superconductivity and Magnetism、Magnetic and transport properties of perovskites and related materials、Advanced Condensed Matter Physics

How Cooper pairs form and condense has been the main challenge in the physics of copper-oxide high-temperature superconductors. Great efforts have been made in the ‘underdoped’ region of the phase diagram, through doping a Mott insulator or cooling a strange metal. However, there is still no consensus on how superconductivity emerges when electron-electron correlations dominate and the Fermi surface is missing. To address this issue, here we carry out high-resolution resonant inelastic X-ray scattering and scanning tunneling microscopy studies on prototype cuprates Bi2Sr2Ca0.6Dy0.4Cu2O8+δ near the onset of superconductivity, combining bulk and surface, momentum- and real-space information. We show that an incipient charge order exists in the antiferromagnetic regime down to 0.04 holes per CuO2 unit, entangled with a particle-hole asymmetric pseudogap. The charge order induces an intensity anomaly in the bond-buckling phonon branch, which exhibits an abrupt increase once the system enters the superconducting dome. Our results suggest that the Cooper pairs grow out of a charge-ordered insulating state, and then condense accompanied by an enhanced interplay between charge excitations and electron-phonon coupling. A major mystery in cuprate superconductors is how Cooper pairs form and condense. Here, the authors use RIXS and STM techniques to reveal that a charge-ordered insulating phase and enhanced bond-buckling phonons play important roles in this process.