Figure 1

Top left panel: Sketch of the EKL, with blocked sites depicted by small spheres and the shaded region representing the unit cell. (a)–(e) Unfolded spectral functions $A(\mathbf{k},\omega )$ [according to Eq. (3)] projected onto $a_{1g}$ orbitals (a)–(d) and onto both $a_{1g}$ and the two $e_g^{\prime }$ orbitals (e) for ${\mathrm{Na}}_{2/3}{\mathrm{CoO}}_2$ ($T=115\mathrm{K}$). (a),(b) Results for ($U=V=0$) on the triangular lattice (a) and on the kagome lattice (b), with the side panels displaying the corresponding $k$-integrated spectral function [projected density of states (pDOS)]. (c)–(e) Results obtained within CDMFT for $U=5\mathrm{eV}$, $V=0$ (c) and for $U=5\mathrm{eV}$, $V=0.3\mathrm{eV}$ (d),(e). The white dotted lines in (a)–(d) represent the QP peak and HE hump extracted from the ARPES data in Refs. 9, 10. In (e) the black dotted lines correspond to the locations of the energy-distribution-curve maxima of the spectral intensity seen at high energies in the bare ARPES data of Refs. 9, 10 (with black bars showing the approximate width of the feature). The quasiparticle and HE hump dotted lines in (e) are the same as in the other panels.Reuse & Permissions

Figure 2

Temperature dependence of $\Gamma /k_{B}T$, with $\Gamma$ the inverse QP lifetime for the kagome cobaltate model with on-site Coulomb interaction $U$ ($V=0$) for different $x$. Inset: $\Gamma /k_{B}T$ for the triangular cobaltate model including distant hoppings at $x=3/4$ (green, circles) and for the kagome lattice with only NN hoppings at $x=2/3$ (magenta, stars).Reuse & Permissions

Figure 3

Doping dependence of $Z$ for the symmetric molecular orbital $|u⟩$ of the kagome cobaltate model at $T=39\mathrm{K}$. Crosses: single-site calculations, thus $Z_u=Z_d=Z$; triangles, circles, boxes: cluster calculations. All lines are just guides to the eye. Inset: The local spectral function projected onto the $a_{1g}$ orbital with $V$ at $x=3/4$.Reuse & Permissions