  Modulations of interfacial Dzyaloshinskii-Moriya interaction (iDMI) on
current-driven dynamics of 180$^{\circ}$ domain walls (180DWs) in long and
narrow spin valves (LNSVs) with heavy-metal caplayers are systematically
investigated. We focus on LNSVs with in-plane magnetic anisotropy in their free
layers. For planar-transverse polarizers (pinned layers of LNSVs), the Walker
breakdown can be postponed considerably (practical infinity) by iDMI. More
interestingly, the originally unstable traveling mode is also stabilized by
iDMI with high saturation velocity thus serves as fast carrier of information.
For parallel polarizers, the Walker limit is increased and the corresponding
modifications of iDMI to wall velocity in both steady and precessional flows of
180DWs are provided. For perpendicular polarizers, precessional flow of 180DWs
is absent due to the stability of stationary mode beyond the modified Walker
limit. For LNSVs with perpendicular magnetic anisotropy in their free layers,
similar results are obtained. Our findings open new possibilities for
developing magnetic nanodevices based on 180DW propagation with low energy
consumption and high robustness.
