Spin-transfer torque driven motion of domain-wall skyrmions in a fixed channel: Controllable dynamics by in-plane current directions

Domain-wall skyrmions (DWSks) hold great promise for high-density spintronic applications; however, how their intrinsic spin texture governs their dynamical behavior remains an open question. By combining micromagnetic simulations with the Thiele formalism, we systematically investigate the dynamics of DWSks driven by spin-transfer torque under various in-plane current directions within a fixed domain-wall channel. We develop a theoretical model that accurately captures the steady-state velocity of DWSks and demonstrate that their non-axisymmetric cusp structure induces direction-dependent dissipation constants (Dxx↑≠Dxx↓), which consequently result in asymmetric velocity magnitudes for opposite current directions. Our theoretical predictions are in excellent agreement with micromagnetic simulations, and the proposed model proves to be robust against variations in material parameters and driving mechanisms. This work offers theoretical insights into the precise control of DWSk motion and provides guidelines for the design of advanced spintronic devices.