Fig. 4: Domain-like arrangement of trion valley polarization.
a Illustration of the trion degree of circular polarization (DOCP), with indications of the spatial arrangement of trion valley polarization at various points on the curve. Above ∣Bsat∣, the CrBr3 is in a single domain state and there is a uniform spin preference for electron tunneling from MoSe2 to CrBr3. At lower B-fields, the relative strengths of spin ↑ or ↓ tunneling may be fine-tuned by control of the external field, which determines the relative spatial area occupied by adjacent domains. The red circles indicate an approximation of the laser spot area in the PL study, about 5 μm2, over which the domain behavior is averaged. b Polar magneto-optical Kerr effect (MOKE) signal from the same sample, with a much smaller measurement area of 0.5 μm2. The domain nucleation behavior is retained, indicating a very small length scale of domains.
