High mobility in a van der Waals layered antiferromagnetic metal

Van der Waals (vdW) materials with magnetic order have been heavily pursued for fundamental physics as well as for device design. Despite the rapid advances, so far, they are mainly insulating or semiconducting, and none of them has a high electronic mobility-a property that is rare in layered vdW materials in general. The realization of a high-mobility vdW material that also exhibits magnetic order would open the possibility for novel magnetic twistronic or spintronic devices. Here, we report very high carrier mobility in the layered vdW antiferromagnet GdTe₃. The electron mobility is beyond 60,000 cm² V^-1 s^-1, which is the highest among all known layered magnetic materials, to the best of our knowledge. Among all known vdW materials, the mobility of bulk GdTe₃ is comparable to that of black phosphorus. By mechanical exfoliation, we further demonstrate that GdTe₃ can be exfoliated to ultrathin flakes of three monolayers.