Temperature and Doping Dependence of the High-Energy Kink in Cuprates

It is shown that spectral functions within the extended $t\mathrm{\text{−}}J$ model, evaluated using the finite-temperature diagonalization of small clusters, exhibit the high-energy kink in single-particle dispersion consistent with recent angle-resolved photoemission results on hole-doped cuprates. The kink and waterfall-like features persist up to large doping and to temperatures beyond $J$; hence, the origin can be generally attributed to strong correlations and incoherent hole propagation at large binding energies. In contrast, our analysis predicts that electron-doped cuprates do not exhibit these phenomena in photoemission.

Figure 1

Weight map of $A(\mathbf{k},\omega )$ vs $\mathbf{k}$ along symmetry lines in the Brillouin zone for $c_h=0.1$ and different $T/t$.

Figure 2

Weight map of $A(\mathbf{k},\omega )$ vs $\mathbf{k}$ along symmetry lines for fixed $T/t=0.2$ and different hole dopings $c_h$.

Figure 3

(a) Damping function $-{\Sigma }^{\prime \prime }(\mathbf{k},\omega )$ and (b) pole location function $b_{\mathbf{k}}(\omega )=\omega -{\zeta }_{\mathbf{k}}-{\Sigma }^{\prime }(\mathbf{k},\omega )$ corresponding to Fig. 1 for $c_h=0.1$, $\mathbf{k}=(\pi /4,\pi /4)$, and various $T/t=0.1-1$.

Figure 4

$A(\mathbf{k},\omega )$ along the zone diagonal calculated from a simplified model and various $T/t=0$, 0.4, and 0.75.