  We describe the effects of the crossing of the exciton levels in moire
quantum dots in external magnetic field. We demonstrate that the unpolarized
light can create significant dynamic valley polarization of interlayer excitons
in the conditions where the Zeeman energy is much smaller than the thermal
energy. The angular momentum is gained by the excitons from the nuclear spin
fluctuations. In the $n$-type moire quantum dots for the typical experimental
parameters, the unpolarized light can lead to the complete valley polarization
of the resident electrons.
