A relation between the resonance neutron peak and ARPES data in cuprates

TL;DR

This paper links the neutron resonance peak and ARPES spectral features in cuprates as manifestations of the same spin fluctuation feedback effect in a $d$-wave superconductor, using a strong coupling spin-fermion model.

Contribution

It demonstrates that both neutron and ARPES features originate from the same physical mechanism within a strong coupling spin-fermion framework, unifying two experimental observations.

Findings

Resonance peak energy is proportional to inverse correlation length.

Peak-dip separation in ARPES equals the resonance energy.

Spin fluctuations cause the peak/dip/hump spectral features.

Abstract

We argue that the resonant peak observed in neutron scattering experiments on superconducting cuprates and the peak/dip/hump features observed in ARPES measurements are byproducts of the same physical phenomenon. We argue that both are due to feedback effects on the damping of spin fluctuations in a $d-$wave superconductor. We consider the spin-fermion model at strong coupling, solve a set of coupled integral equations for fermionic and bosonic propagators and show that the dynamical spin susceptibility below $T_c$ possesses the resonance peak at $\Omega_{res} \propto \xi^{-1}$. The scattering of these magnetic excitations by electrons gives rise to a peak/dip/hump behavior of the electronic spectral function, the peak-dip separation is exactly $\Omega_{res}$.