Calculated Momentum Dependence of Zhang-Rice States in Transition Metal Oxides

Using a combination of local density functional theory and cluster exact diagonalization based dynamical mean field theory, we calculate many-body electronic structures of several Mott insulating oxides including undoped high $T_c$ materials. The dispersions of the lowest occupied electronic states are associated with the Zhang-Rice singlets in cuprates and with doublets, triplets, quadruplets, and quintets in more general cases. Our results agree with angle resolved photoemission experiments including the decrease of the spectral weight of the Zhang–Rice band as it approaches $\mathbf{k}=0$.

Figure 1

Calculated low-energy excitations in ${\mathrm{Sr}}_2{\mathrm{CuO}}_2{\mathrm{Cl}}_2$ (top) and ${\mathrm{La}}_2{\mathrm{CuO}}_4$ (bottom) using LDA plus single-site DMFT (dashed line) and two-site cluster DMFT (solid line). The experimental data are from: Ref. 19 (open circles), Ref. 18 (open triangles), Ref. 20 (open squares). The solid linewidth shows the oxygen content, while the numbers indicate the amount of electrons in the ZR band.

Figure 2

Comparison between calculated quasiparticle dispersions using $\mathrm{LDA}+\mathrm{DMFT}$ and the photoemission data [5, 23] for paramagnetic state of NiO. The solid linewidth and the numbers show the oxygen content and the amount of electrons in the ZR band.

Figure 3

The same as Fig. 2 but for CoO. Photoemission data are from Ref. 25, 26.