Constituents of the "kink" in high-Tc cuprates

TL;DR

This paper investigates the temperature and doping dependence of the 70 meV kink in high-Tc cuprates, attributing it mainly to spin-fluctuation interactions that evolve with temperature and doping.

Contribution

It provides a detailed analysis of the quasiparticle spectrum and clarifies the constituents of the kink, emphasizing the role of spin fluctuations in high-Tc cuprates.

Findings

The 70 meV kink shows strong temperature and doping dependence.

Spin fluctuations are the main contributors to the kink formation.

The self-energy evolution aligns with the spin-fluctuation spectrum.

Abstract

Applying the Kramers-Kronig consistent procedure, developed earlier, we investigate in details the formation of the quasiparticle spectrum along the nodal direction of high-Tc cuprates. The heavily discussed "70 meV kink" on the renormalized dispersion exhibits a strong temperature and doping dependence when purified from structural effects. This dependence is well understood in terms of fermionic and bosonic constituents of the self-energy. The latter follows the evolution of the spin-fluctuation spectrum, emerging below T* and sharpening below Tc, and is the main responsible for the formation of the kink in question.