Spin-selective evolution of the Zhang-Rice state in binary transition metal oxide MnO(001) film
Here, the Zhang-Rice (ZR) state is a strongly hybridized bound state formed by transition-metal and oxygen atoms. The spin fluctuations within the ZR state are known to play an important role in high-T c superconductivity in cuprates. Here, we employ a combination of angle-resolved photoemission spectroscopy (ARPES), x-ray photoemission spectroscopy (XPS), and ab initio embedded dynamical mean-field theory (eDMFT) to investigate the influence of magnetic ordering on the spectral characteristics of the valence band and Mn 2p core-level in MnO (001) ultrathin films. Our results demonstrate that a complex spin-selective evolution of Mn 3d-O2p hybridization develops due to the long-range antiferromagnetic (AFM) ordering. This hybridization significantly alters the spectral shape and weight of the ZR state. Specifically, in the AFM phase, we observed the sharpening of the ZR state and band folding with the periodicity of the AFM unit cell of MnO(001). We also demonstrated a strong connection between the spectral evolution of the ZR state and the non-local screening channels of the photoexcited core holes. Further, our detailed temperature-dependent study reveals the presence of short-range antiferromagnetic correlations that exist at much higher temperatures than Neel temperature (T N ) and shows the evolution of the ZR state across the magnetic transitions and its implication to the core-hole screening in 3d binary transition metal oxides.