  The generation of photocurrent in an ideal two-dimensional Dirac spectrum is
symmetry-forbidden. In sharp contrast, we show that three-dimensional Weyl
semimetals can generically support significant photocurrent generations due to
the combination of inversion symmetry breaking and finite tilts of the Weyl
spectra. Symmetry properties, chirality relations and various dependences on
the system and light sources are explored in details. Our results suggest that
noncentrosymmetric Weyl materials can be advantageously applied to room
temperature detections of mid- and far-infrared radiations.
