In the cuprates, one-dimensional chain compounds provide a unique opportunity to understand the microscopic physics due to the availability of reliable theories. However, progress has been limited by the inability to controllably dope these materials. Here, we report the synthesis and spectroscopic analysis of the one-dimensional cuprate Ba2−xSrxCuO3+δ over a wide range of hole doping. Our angle-resolved photoemission experiments reveal the doping evolution of the holon and spinon branches. We identify a prominent folding branch whose intensity fails to match predictions of the simple Hubbard model. An additional strong near-neighbor attraction, which may arise from coupling to phonons, quantitatively explains experiments for all accessible doping levels. Considering structural and quantum chemistry similarities among cuprates, this attraction will play a similarly crucial role in the high-TC superconducting counterparts
@article{arxiv.2106.14272,
title = {Anomalously Strong Near-Neighbor Attraction in Doped 1D Cuprate Chains},
author = {Zhuoyu Chen and Yao Wang and Slavko N. Rebec and Tao Jia and Makoto Hashimoto and Donghui Lu and Brian Moritz and Robert G. Moore and Thomas P. Devereaux and Zhi-Xun Shen},
journal= {arXiv preprint arXiv:2106.14272},
year = {2021}
}