Effect of electronic correlation on the spin-transfer torque

We propose to investigate the role of electron-electron correlations in spin-transfer torque systems. Spin polarized currents act with a spin-transfer torque on a magnetic scatterer such as a magnetic junction or a domain wall which may switch the magnetic order of these objects. When realizing this effect in nanowires or nanoislands one has to inspect carefully the influence of electronic correlation (which is known to be dominant in such low dimensional structures). We aim in this project to study the interplay between electronic correlation and dc or ac-current-induced magnetic dynamics in nanowires containing a multiple of domain walls. Our initial investigations indicate that the effect of the spin-transfer torque is modified by having several domain walls, as realized experimentally in the so-called racetrack memory where many domain walls are used to alter the current through wires and thus to in-code information. Our pilot calculations for an idealized system show that electronic correlations result in nontrivial interactions between the domain walls and hence a qualitatively different behaviour at low dimensions.