Quasiparticle scattering rate in overdoped superconducting cuprates

Abstract

We calculate the quasiparticle scattering rate in the superconducting state of the overdoped cuprates, in the context of the Eliashberg formalism for a Fermi liquid with strong van Hove singularities close to the chemical potential. For a d x 2 −y 2 superconducting gap, we demonstrate analytically that the scattering rate is linear in the maximum of temperature or energy, but with different intercepts and momentum dependence, thus extending our earlier results on the normal state. We discuss our results in view of angle-resolved photoemission experiments. We also comment on the case of a s-wave gap.The nature of the carriers in the cuprates is an important question, which has been discussed and debated extensively. The availability of relevant experimental data over the years, and in particular angle-resolved photoemission (ARPES), should be helpful in the effort towards achieving a better understanding of this question.Here, we look at a characteristic one-particle property, relevant to ARPES. We obtain analytically the scattering rate in the superconducting state for a Fermi liquid with strong density of states peaks -van-Hove singularities (vHs) in 2-D -located close to the chemical potential µ. Incidentally, this model does not apply to the underdoped cuprates, as there is no indication that a Fermi liquid description is appropriate. The qualitative nature of our results does not depend on the doping level, for as long as we remain within the realm of Fermi liquid theory. Precise numerical calculations can yield the quantitative dependence of the theory on the doping etc. A review of related work in the frame of the so-called van-Hove scenario has been given in 1 . The pinning of the vHs close to µ seems to be a plausible explanation for the common characteristics of a good many cuprates, whose van-Hove singularities are located between 10-30 meV below the Fermi surface 2 , as ARPES experiments have shown. A review of some calculations yielding the pinning of the vHs close to µ appears in 3 . The present work extends our results for the normal state, obtained in 3,4 , to the superconducting state. The analysis presented below can also be done in the frame of a weak-coupling BCS-type approach. We opt for the intermediate to strong-coupling Eliashberg approach, which is relevant for the cuprates. Qualitatively, i.e. as far as power laws etc. are concerned in terms of energy and temperature, the answers are the same for the two approaches.We consider a generic dispersion appropriate for the cuprates, of the type t, t ′ , t ′′

Observation of non-Fermi liquid behavior in hole-dopedLiFe1−xVxAs

“…The observation of a NFL behavior without quantum critical point in both Co-doped and V-doped LiFeAs is consistent with a recent theoretical study emphasizing on the impact of nesting on the temperature evolution of the electrical conductivity [24]. We caution though that the linear resistivity in the cuprates was previously derived in the context of a FL with a large density-of-states (like a van Hove singularity) near E F [25,26], a condition that also applies to Fe-based superconductors near good nesting conditions. As shown in Fig.…”

Consistent Description of the Metallic Phase of Overdoped Cuprate Superconductors as an Anisotropic Marginal Fermi Liquid

“…First, a weak coupling treatment of the Hubbard model produces an anisotropic scattering rate of similar frequency and angular dependence. The MFL component arises from a nesting of the Fermi surface in the anti-nodal regions [32] or from proximity to a van Hove singularity [32,33]. However, for the later case the resulting scattering rate would have opposite doping dependence and would appear only at higher T than experimentaly observed for Tl2201.…”

Unmasking the nodal quasiparticle dynamics in cuprate superconductors using low-energy photoemission

“…2(d) and 4(b) is related with the opening of the d-wave gap. 20,21,22 Considering that the electronic density of states is proportional to |ω| at low energies, the elastic scattering rate may have an ω-linear term, 20 while the inelastic scattering rates only have higher order terms, as convolved with the energy distribution of the coupling modes. The predominance of the odd scattering process at low energies 14 is not confirmed by our data.…”