1202.2596 (Tanmoy Das et al.)

Crossover from inelastic magnetic scattering of Cooper pairs to
spin-wave dispersion produces low-energy kink in cuprates    [PDF]

Tanmoy Das, R. S. Markiewicz, A. Bansil

We present GW based self-energy calculations for the state of coexisting
spin-density wave and d-wave superconductivity in a series of cuprate
superconductors. In these systems, the spin resonance spectrum exhibits the
typical `hour-glass' form, whose upward and downward dispersion branches come
from the gapped spin-wave and magnetic scattering of Cooper pairs,
respectively. We show that the crossover between these two different dispersion
features leads to an abrupt change in slope in the quasiparticle self-energy,
and hence the low-energy kink commences in the single-particle quasiparticle
spectrum. The calculated electron-bosonic coupling strength agrees well with
experimental data as a function of temperature, doping and material. The
results demonstrate that the electronic correlations dominate the quasiparticle
spectra of cuprates near the low-energy kink, suggesting a relatively smaller
role for phonons in this energy range.

View original: http://arxiv.org/abs/1202.2596