Control of localized states of itinerant electrons and their magnetic interactions

TL;DR

This paper demonstrates that electric fields can control the magnetic states of nanosystems by shifting energy levels, enabling manipulation of magnetic properties without current flow, with implications for spintronics.

Contribution

It introduces a model showing electric-field control of magnetic states in nanosystems through energy level shifts, independent of spin-orbit effects.

Findings

Magnetic states depend on the d-level position relative to the Fermi level.

Electric fields can switch magnetic states without current flow.

Multiple stable magnetic configurations can coexist for certain parameters.

Abstract

Controlling the magnetic properties of nanosystems by an electric field offers a number of advantages for spintronics applications. Using the noncollinear Alexander-Anderson model, we have shown that the interaction of localized magnetic moments formed by itinerant electrons strongly depends on the position of the d-level relative to the Fermi level, which determines the number of localized electrons. Depending on this parameter, the ground state of the magnetic dimer can be ferromagnetic, antiferromagnetic, or noncollinear without the effects of spin-orbit interaction. The magnetic state can be controlled by shifting the d-level with an electric field, even without current flow. For a sufficiently large value of the hopping parameter between localized states there can be several self-consistent solutions with different values of magnetic moments. This opens new possibilities for manipulation of the magnetic structure of nanosystems. The results obtained lead to a new interpretation of the mechanisms of magnetization reversal, recording, and deleting of magnetic structures in tunneling spectroscopy experiments.