Mesoscopic mechanism of exchange interaction in magnetic multilayers

TL;DR

This paper investigates a mesoscopic mechanism of exchange interaction in ferromagnet-normal metal-ferromagnet multilayers, revealing that the relative magnetization orientation becomes perpendicular when the metal thickness exceeds the electron mean free path, with exchange energy decaying as a power law.

Contribution

It introduces a mesoscopic perspective on exchange interactions, showing how metal thickness influences magnetization orientation and energy decay in multilayer structures.

Findings

Magnetizations tend to be perpendicular when metal thickness exceeds electron mean free path.

Exchange energy decays with metal thickness following a power law.

The mechanism differs from classical exchange interaction models.

Abstract

We discuss a mesoscopic mechanism of exchange interaction in ferromagnet-normal metal-ferromagnet multilayers. We show that in the case when the metal's thickness is larger than the electron mean free path, the relative orientation of magnetizations in the ferromagnets is perpendicular. The exchange energy between ferromagnets decays with the metal thickness as a power law.