Anisotropic scattering rates and antiferromagnetic precursor effects in the t-t'-U Hubbard model

Abstract

We have investigated the evolution of the electronic properties of the t-t'-U Hubbard model with hole doping and temperature. Due to the shape of the Fermi surface, scattering from short wavelength spin fluctuations leads to strongly anisotropic quasi-particle scattering rates at low temperatures near halffilling. As a consequence, significant variations with momenta near the Fermi surface emerge for the spectral functions and the corresponding ARPES signals. At low doping the inverse lifetime of quasiparticles on the Fermi surface is of order kBT varying linearly in temperature from energies of order t down to a very low energy scale set by the spin fluctuation frequency while at intermediate doping a sub-linear T -dependence is observed. This behavior is possibly relevant for the interpretation of photoemission spectra in cuprate superconductors at different hole doping levels.

Electron-doping versus hole-doping in the 2D t-t' Hubbard model

“…In comparison with the model assumptions in [13] we note that our calculations at temperatures above the flow to strong coupling yield a smaller anisotropy in the scattering rates and no T 2 behavior for the quasiparticles in the BZ diagonal. Our data resemble more FLEX results obtained by Kontani et al [17] Altmann et al [19]. The first group was able to describe resistivity and Hall coefficients in qualitative agreement with the experiments.…”

Theory of electronic Raman scattering in nearly antiferromagnetic Fermi liquids

“…For the z=2 scaling regime, the inverse slope is proportional to T down to the lowest temperatures reachable for our level of numerical accuracy, while for the z = 1 regime, the inverse slope appears to extrapolate to a non-zero value at T = 0. This is also seen in FLEX calculations [11]. A simple connection between these and the perturbative results is that the self consistency leads to a strong downward renormalization of ω sf and a much lower crossover T * to Fermi liquid-like behavior.…”

“…This interaction forms the basis of the NAFL theory, and has been derived by considering the interaction of electrons to external spin degrees of freedom [21,13] and decribes at low temperatures and several dopings the effective interaction calculated via FLEX [11] and Quantum Monte Carlo [22] treatments of the 2D Hubbard model. Recently the optical conductivity was explored within this model and was found to be in relatively good agreement with experiments [14].…”

“…Large qp scattering for momentum transfers near the AF wave-vector Q = π/a, π/a have been invoked to explain the photo-emission results [10,11]. Therefore we have studied the phenomenological Nearly Antiferromagnetic Fermi Liquid (NAFL) model [12] as an example of highly anisotropic scattering to investigate the two-particle Raman response.…”

Angle-resolved photoemission spectra of the Hubbard model

“…In addition, one observes a rather large residual scattering rate for both momenta k a and k b . This can either be taken as further evidence for NFL behavior or as signal for the occurrence of a new very small low-energy scale 32 . Obviously, we cannot decide this question on the basis of the present data, but would have to look at much lower temperatures.…”