| Domain Wall Resistance |
| Domain-wall resistance in ferromagnetic (Ga,Mn)As | |
| A series of microstructures designed to pin domain-walls (DWs) in (Ga,Mn)As with perpendicular magnetic anisotropy has been employed to determine extrinsic and intrinsic contributions to DW resistance. The former is explained quantitatively as resulting from a polarity change in the Hall electric field at DW. The latter is one order of magnitude greater than a term brought about by anisotropic magnetoresistance and is shown to be consistent with disorder-induced misstracing of the carrier spins subject to spatially varying magnetization. |
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| Figure.1 | Optical micrographs of (a) unpatterned (device A) and (b) patterned (device B) layers for domain wall resistance measurements. (c) Schematic cross-sectional view under the white line of (b). |
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| Figure.2 | Magnetoresistance of device A (a) and device B (b) at 45 K (current I=30 μA). Insets show MOKE images in various magnetic fields disclosing relation between number of domain-walls and resistance. |
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| Figure.3 | (a) Magnetoresistance of devices C1-C4 (current I=10, 20, 40, 60 μA, respectively) with different channel width w. Solid lines have slopes expected from the negative magnetoresistance of Hall bar device for complete antiparallel orientation of domains, and their extrapolation to H=0 gives domain wall resistance (DWR). (b) DWR vs. 1/w, which provides extrinsic and intrinsic contributions per one DW (Rext. and Rint.Ad), shown by open circles in (c) and (d), respectively. Open triangles in (c) show computed Rext.. Open triangles and inverse triangles in (d) are theoretical calculated assuming that the conductance polarization is equal or 1.2 times greater that thermodynamic polarization, respectively. |
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