Fig. 4: Material and temperature dependence of USMR-SHG signals.
From: Ultrafast unidirectional spin Hall magnetoresistance driven by terahertz light field
a A summary of USMR-SHG amplitudes for samples with different material compositions and thicknesses. The thickness (in nm) of each individual layer is indicated on the horizontal axis label. b Temperature dependence of the USMR-SHG signal, represented as the \({E}_{USMR}^{2\Omega }/{E}_{ISHE}^{2\Omega }\) ratio, to exclude experimental artifacts related to the drift of the overall signal due to thermal contractions. The grey shaded area indicates the noise floor limit. All USMR-SHG components were measured in the horizontal magnetisation geometry (Fig. 1(d)) at an angle of ϕ = 45°. The thermally driven SHG signal was measured in the vertical magnetisation geometry (Fig. 1c) with a vertically polarised THz pump pulse.
