The commensurate magnetic excitations induced by band-splitting and Fermi surface topology in n-type Cuprates

TL;DR

This study investigates magnetic excitations in n-type cuprates, revealing that band-splitting and Fermi surface topology cause commensurate magnetic excitations, independent of superconductivity, highlighting the importance of antiferromagnetic correlations.

Contribution

The paper demonstrates that commensurate magnetic excitations in n-type cuprates originate from band-splitting and Fermi surface topology, independent of d-wave superconductivity.

Findings

Magnetic excitations are commensurate at low energy and become spin wave-like at higher energy.

Commensurability arises from band splitting and Fermi surface topology.

The behavior is a normal state property, not related to superconductivity.

Abstract

The antiferromagnetic correlation plays an important role in high-T$_{c}$ superconductors. Considering this effect, the magnetic excitations in n-type cuprates near the optimal doping are studied within the spin density wave description. The magnetic excitations are commensurate in the low energy regime and further develop into spin wave-like dispersion at higher energy, well consistent with the inelastic neutron scattering measurements. We clearly demonstrate that the commensurability originates from the band splitting and Fermi surface topology. The commensurability is a normal state property, and has nothing to do with d-wave superconductivity. The distinct behaviors of magnetic excitation between the n-type and p-type cuprates are further discussed. Our results strongly suggest the essential role of antiferromagnetic correlations in the cuprates.