Stochastic and complex depinning dynamics of magnetic domain walls

We study the thermally induced depinning process of a single magnetic domain wall (DW) under applied field when the DW is trapped by a notch made in a nanowire shaped from a spin-valve multilayer with in-plane magnetization. In such devices depinning is typically a stochastic process and the depinning field distribution exhibits complex features. By analyzing simultaneously depinning field distributions and relaxation data, we observe two distinct sources of complexity in DW depinning processes: multiplicity in the DW structure and fundamental complexity in the depinning process.