We present an angle-resolved photoemission spectroscopy study of the single-layer T*-type structured cuprate SmLa1−xSrxCuO4 with unique five-fold pyramidal oxygen coordination. Upon varying oxygen content, T*-SmLa1−xSrxCuO4 evolved from a Mott-insulating to a metallic state where the Luttinger sum rule breaks down under the assumption of a large hole-like Fermi surface. This is in contrast with the known doping evolution of the structural isomer La2−xSrxCuO4 with six-fold octahedral coordination. In addition, quantitatively characterized Fermi surface suggests that the empirical Tc rule for octahedral oxygen-coordination systems does not apply to T*-SmLa1−xSrxCuO4. The present results highlight unique properties of the T*-type cuprates possibly rooted in its oxygen coordination, and necessitate thorough investigation with careful evaluation of disorder effects.
@article{arxiv.2306.13251,
title = {Influence of oxygen-coordination number on the electronic structure of single-layer La-based cuprates},
author = {M. Horio and X. Peiao and M. Miyamoto and T. Wada and K. Isomura and J. Osiecki and B. Thiagarajan and C. M. Polley and K. Tanaka and M. Kitamura and K. Horiba and K. Ozawa and T. Taniguchi and M. Fujita and I. Matsuda},
journal= {arXiv preprint arXiv:2306.13251},
year = {2023}
}