Weyl semimetal generated from Dirac semimetal using off-resonant light

We propose a simple realization of a three-dimensional Weyl semimetal phase using off-resonant circularly polarized light in the three dimensional Dirac semimetals. Using both analytical and numerical methods, we show that a fourfold degenerate Dirac node can be further evolved into two Weyl nodes in the context of low energy Hamiltonian. The distance between the two Weyl nodes in momentum space can be controlled by the intensity and frequency of the light. Meanwhile, because this distance is proportional to the relatively large Fermi velocity, the typical character of the Weyl semimetal, such as surface Fermi arc, can be observed obviously.