Suppression of the Weak-Localization Effect due to a Domain Wall in Mesoscopic Wires of Ferromagnetic Metals

Abstract

We study the weak-localization (WL) effect in mesoscopic wires of ferromagnetic metals, focusing on the decoherence caused by a magnetic domain wall (DW). The decoherence leads to suppression of the WL correction to conductance. A real-space approach is presented to describe the WL effect which explicitly takes into account the location of a DW. If the length L of a wire is much smaller than the phase coherence length L_φ, the WL correction is shown to depend on the location of the DW. In the opposite limit of L >> L_φ >> W (W: thickness of the DW), it is shown that the DW reduces the WL correction by a factor of (1-W/2L) compared with that in the absence of the DW. The influence of the DW on the amplitude of the Altshuler-Aronov-Spivak oscillation in a metallic ring partially replaced by a ferromagnetic wire is also discussed.