  The spin Hall effect (SHE), in which electrical current generates transverse
spin current, plays an important role in spintronics for the generation and
manipulation of spin-polarized electrons. The phenomenon originates from
spin-orbit coupling. In general, stronger spin-orbit coupling favors larger
SHEs but shorter spin relaxation times and diffusion lengths. To achieve both
large SHEs and long-range spin transport in a single material has remained a
challenge. Here we demonstrate a giant intrinsic SHE in AB-stacked MoTe2/WSe2
moir\'e bilayers by direct magneto optical imaging. Under moderate electrical
currents with density < 1 A/m, we observe spin accumulation on transverse
sample edges that nearly saturates the spin density. We also demonstrate
long-range spin Hall transport and efficient non-local spin accumulation
limited only by the device size (about 10 um). The gate dependence shows that
the giant SHE occurs only near the Chern insulating state, and at low
temperatures, it emerges after the quantum anomalous Hall breakdown. Our
results demonstrate moir\'e engineering of Berry curvature and large SHEs for
potential spintronics applications.
