Evaluation of bulk-interface contributions to Edelstein magnetoresistance at metal/oxide interfaces

Abstract

We report a systematic study on Edelstein magnetoresistance (Edelstein MR) in $\mathrm{C}{\mathrm{o}}_{25}\mathrm{F}{\mathrm{e}}_{75}\text{/}\mathrm{Cu}\text{/}\mathrm{B}{\mathrm{i}}_{2}{\mathrm{O}}_{3}$ heterostructures with a strong spin-orbit interaction at the $\mathrm{Cu}\text{/}\mathrm{B}{\mathrm{i}}_{2}{\mathrm{O}}_{3}$ interface. We succeed in observing a significant dependence of the Edelstein MR on both Cu layer thickness and temperature, and also develop a general analytical model considering distinct bulk and interface contributions on spin relaxation. Our analysis, based on the above model, quantitatively illustrates a unique property of the spin transport near the Rashba interface, revealing a prominent role of the spin relaxation process by determining the ratios of the spin relaxation inside and outside the interface. We further find the characteristic spin transport is unaffected by temperature. Our results provide an essential tool for exploring the transport in a system with spin-momentum-locked two-dimensional states.