  We investigate the c-direction conduction in CrSBr in the linear regime, not
accessible in other van der Waals (vdW) magnetic semiconductors, because of the
unmeasurably low current. The resistivity -- $10^8$ to $10^{11}$ times larger
than in the a- and b-directions -- exhibits magnetic state dependent thermally
activated and variable range hopping transport. In the spin-flip phase at 2 T,
the activation energy is 20 meV lower than in the antiferromagnetic state, due
to a downshift of the conduction band edge, in agreement with ab-initio
calculations. In the variable range hopping regime, the average hopping length
decreases from twice the interlayer distance to the interlayer distance at 2 T,
because in the antiferromagnetic state the large exchange energy impedes
electrons hopping between adjacent layers. Our work demonstrates that the
linear transport regime provides new information about electronic processes in
vdW magnetic semiconductors, and shows how magnetism influences these processes
both in real and reciprocal space.
