  We report a very large spin-orbit torque (SOT) capability of chromium-based
transition metal dichalcogenides (TMD) in their Janus forms CrXTe, with X=S,Se.
The structural inversion symmetry breaking, inherent to Janus structures is
responsible for a large SOT response generated by giant Rashba splitting,
equivalent to that obtained by applying a transverse electric field of $\sim
100 \,\text{V} \,\text{nm}^{-1}$ in non-Janus CrTe\textsubscript{2}, completely
out of experimental reach. By performing transport simulations on custom-made
Wannier tight-binding models, Janus systems are found to exhibit a SOT
performance comparable to the most efficient two-dimensional materials, while
allowing for field-free perpendicular magnetization switching owing to their
reduced in-plane symmetry. Altogether, our findings evidence that magnetic
Janus TMDs stand as suitable candidates for ultimate SOT-MRAM devices.
