  Polar molecules are an emerging platform for quantum technologies based on
their long-range electric dipole-dipole interactions, which open new
possibilities for quantum information processing and the quantum simulation of
strongly correlated systems. Here, we use magnetic and microwave fields to
design a fast entangling gate with $>0.999$ fidelity and which is robust with
respect to fluctuations in the trapping and control fields and to small thermal
excitations. These results establish the feasibility to build a scalable
quantum processor with a broad range of molecular species in optical-lattice
and optical-tweezers setups.
