Nodal quasiparticle lifetimes in cuprate superconductors

Abstract

A new generation of angular-resolved photoemission spectroscopy (ARPES) measurements on the cuprate superconductors offers the promise of enhanced momentum and energy resolution. In particular, the energy and temperature dependence of the on-shell nodal (kx=ky) quasiparticle scattering rate can be studied. In the superconducting state, low-temperature transport measurements suggest that one can describe nodal quasiparticles within the framework of a BCS d-wave model by including forward elastic scattering and spin-fluctuation inelastic scattering. Here, using this model, we calculate the temperature and frequency dependence of the on-shell nodal quasiparticle scattering rate in the superconducting state, which determines the momentum width of the ARPES momentum distribution curves. For a zero-energy quasiparticle at the nodal momentum kN, both the elastic and inelastic scattering rate show a sudden decrease as the temperature drops below Tc, reflecting the onset of the gap amplitude. At low temperatures the scattering rate decreases as T3 and approaches a zero-temperature value determined by the elastic impurity scattering. For T>Tc, we find a quasilinear dependence on T. At low reduced temperatures, the elastic scattering rate for the nodal quasiparticles exhibits a quasilinear increase at low energy ω, which arises from elastic scattering processes. The inelastic spin-fluctuation scattering leads to a low-energy ω3 dependence, which, for ω≳3Δ0, crosses over to a quasilinear behavior.

Source-reported materials — not catalogue approval

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