Figure 5: Surface spin photocurrent under spin precession of the injected electrons from GaAs.
(a,c,d) Magnetic-field dependence of 
measured from the S2 device at 5, 20 and 30 K in an applied magnetic field along the y direction, under the excitation with the photon energy above (800 nm) and below (820 nm) the GaAs bandgap to highlight the effect of the spin injection. The data obtained over both wide- and narrow-field ranges are shown in c,d, with the latter being measured with a finer field step. The symbols denote the experimental data and the solid lines are the fitting curves based on equation (3). (b) Temperature dependence of the 
values obtained by fitting the field dependence of 
. The excitation power was kept constant at 40 mW for all measurements. The error bars were received from the least-square-fitting procedure of the field-dependent response of 
using equation (3) for different temperatures.
