From Magnons to the Resonance Peak: Spin Dynamics in High-T_C Superconducting Cuprates by Inelastic Neutron Scattering

TL;DR

This paper reviews how spin dynamics in high-Tc cuprates evolve with doping, highlighting the emergence of a magnetic resonance peak in the superconducting state and the suppression of spin correlations in overdoped samples.

Contribution

It provides a comprehensive overview of inelastic neutron scattering results, linking spin excitations to doping levels and superconducting properties in cuprates.

Findings

Resonance peak energy scales with Tc.

Strong antiferromagnetic fluctuations exist in underdoped and optimally doped regimes.

Spin correlations diminish in overdoped samples.

Abstract

The spin dynamics of high temperature superconductors measured by inelastic neutron scattering is reviewed. The spin susceptibility evolves a lot with increasing doping from the undoped insulating state to the overdoped metallic state. In the superconducting state, a strong magnetic resonance peak occurs in the spin excitation spectrum whose energy is proportional to the superconducting temperature. In underdoped and optimally doped regimes, normal state antiferromagnetic fluctuations are observed, proving the existence of strong electronic correlations in cuprates. They are characterized by a spin pseudo-gap. In contrast, these dynamical spin correlations vanish in overdoped samples.