Measuring Domain Wall Fidelity Lengths Using a Chirality Filter

E. R. Lewis, D. Petit, A.-V. Jausovec, L. O’Brien, D. E. Read, H. T. Zeng, and R. P. Cowburn

Phys. Rev. Lett. 102, 057209 – Published 6 February 2009

Abstract

The motion of transverse domain walls (DWs) in thin Permalloy nanowires has been studied by locally detecting the chirality of the moving DW, using a cross-shaped trap acting as a chirality filter. We find that structural changes of the DW occur over a characteristic minimum distance: the “DW fidelity length.” The measured field dependence of the fidelity length is in good qualitative agreement with a 1D analytical model and with published results of numerical simulations and experiments. We also demonstrate extension of the fidelity length to meter length scales using a series of filters.