Trilayer cuprates hold the record for the highest superconducting critical temperatures (Tc), yet the underlying mechanism remains elusive. Using time- and angle-resolved photoemission spectroscopy (tr-ARPES), we uncover a striking interplay between charge order, superconducting gap magnitude, and quasiparticle coherence in Bi2Sr2Ca2Cu3O10+δ (Bi2223). This constitutes ARPES-based evidence of charge order on the inner CuO2 plane, as confirmed via resonant x-ray scattering (RXS); in addition, the same inner plane hosts a superconducting gap significantly larger than that of the overdoped outer planes, firmly establishing it as underdoped. Unexpectedly, despite its underdoped nature, the inner plane also exhibits an exceptional degree of quasiparticle coherence; suppressing charge-order fluctuations further enhances this, making it comparable to that of the overdoped outer planes at elevated electronic temperatures. These findings, supported by complementary three-layer single-band Hubbard calculations, reveal a unique interlayer mechanism in which both pairing strength and phase coherence are optimized when interfacing planes with distinct hole concentrations, providing new microscopic insight into the record Tc of Bi2223.
@article{arxiv.2506.01448,
title = {Enhanced coherence and layer-selective charge order in a trilayer cuprate superconductor},
author = {S. Smit and M. Bluschke and P. Moen and N. Heinsdorf and E. Zavatti and G. Bellomia and S. Giuli and S. K. Y. Dufresne and C. T. Suen and V. Zimmermann and C. Au-Yeung and S. Zhdanovich and J. I. Dadap and M. Zonno and S. Gorovikov and H. Lee and C-T. Kuo and J-S. Lee and D. Song and S. Ishida and H. Eisaki and B. Keimer and M. Michiardi and I. S. Elfimov and G. Levy and D. J. Jones and M. Capone and A. Damascelli},
journal= {arXiv preprint arXiv:2506.01448},
year = {2025}
}