Linear Magnetic Response of Disordered Metallic Rings: Large Contribution from Forward Scattering Interactions

TL;DR

This paper investigates how forward scattering electron-electron interactions influence the magnetic response of disordered metallic rings, revealing they can dominate over large momentum transfer interactions within certain regimes.

Contribution

It demonstrates that forward scattering interactions significantly impact the magnetic response, surpassing large momentum transfer effects in specific experimental conditions.

Findings

Forward scattering interactions can dominate the magnetic response.

Large momentum transfer processes are dominant outside linear response regime.

The Landau parameter F_0 for copper influences the interaction effects.

Abstract

We calculate the effect of electron-electron interactions involving vanishing momentum transfer (forward scattering) on the orbital linear magnetic response of disordered metal rings pierced by a magnetic flux phi. Using the bulk value of the Landau parameter F_0 for copper, we find that in the experiment by L\'{e}vy {\it{et al.}} [Phys. Rev. Lett. {\bf{64}}, 2074 (1990)] the forward scattering contribution to the linear magnetic response is larger than the corresponding contribution from large momentum transfers considered by Ambegaokar and Eckern [Phys. Rev. Lett. {\bf{65}}, 381 (1990)]. However, outside the regime of validity of linear response and to first order in the effective screened interaction the persistent current is dominated by scattering processes involving large momentum transfers.