Slonczewski-spin-current driven dynamics of 180$^{\circ}$ domain walls in spin valves with interfacial Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates how interfacial Dzyaloshinskii-Moriya interaction and Slonczewski spin currents influence the dynamics of 180-degree domain walls in spin valves, revealing new control mechanisms for magnetic nanodevices.

Contribution

It introduces a detailed analysis of 180DWs dynamics under various polarizer orientations considering IDMI and Slonczewski currents, highlighting novel control strategies.

Findings

Stronger spin polarization increases Walker limit and steady flow stability.

IDMI causes stable-region flapping and width enlargement.

High differential mobility of 180DWs persists under certain polarizer configurations.

Abstract

Steady-flow dynamics of ferromagnetic 180$^{\circ}$ domain walls (180DWs) in long and narrow spin valves (LNSVs) with interfacial Dzyaloshinskii-Moriya interaction (IDMI) under spin currents with Slonczewski $g-$factor are examined. Depending on the magnetization orientation of polarizers (pinned layers of LNSVs), dynamics of 180DWs in free layers of LNSVs are subtly manipulated: (i) For parallel polarizers, stronger spin polarization leads to higher Walker limit thus ensures the longevity of faster steady flows. Meantime, IDMI induces both the stable-region flapping and its width enlargement. (ii) For perpendicular polarizers, a wandering of 180DWs between bi- and tri-stability persists with the criticality adjusted by the IDMI. (iii) For planar-transverse polarizers, IDMI makes the stable region of steady flows completely asymmetric and further imparts a high saturation wall velocity under large current density. Under the last two polarizers, the ultrahigh differential mobility of 180DWs survives. The combination of Slonczewski spin current and IDMI provides rich possibilities of fine controlling on 180DW dynamics, hence opens avenues for magnetic nanodevices with rich functionality and high robustness.