Electron spectral function of high-temperature cuprate superconductors

We address the doping evolution of the low energy electronic structure of high-temperature superconducting copper-oxide compounds, as described by the tt′t″ J model. Following experimental evidence for well defined quasiparticles in the normal state of these doped Mott insulators, we use a new slave-particle basis that includes electron-like operators, namely, the doped-carrier basis, and extensively discuss the mean-field electron spectral function of the tt′t″ J model. We show that the above mean-field theory reproduces many aspects of the non-trivial microscopic single electron dynamics probed by angle-resolved photoemission experiments in hole and electron doped cuprates; these include: the emergence of spectral peaks inside the Mott gap upon doping away from half-filling; the differentiation between the nodal and antinodal regions of momentum space, which displays distinct properties in the hole and electron doped regimes; the low energy spectral weight arcs, whose length increases with doping; the nodal dispersion kink, which is sharper in the underdoped regime; the strong dispersion renormalization, which renders the dispersion close to (0,π) and (π, 0) surprisingly flat. We further argue that measured angle-resolved photoemission spectral dispersions, together with the associated spectral weight intensity, impose strong constraints on the character of coexisting short-range correlations. The agreement between our results and experimental data supports that the two predominant local spin correlations in cuprate superconductors are: (i) d-wave singlet pairing correlations, and (ii) staggered moment correlations.