Abstract
It is supposed that at very small scales a quantum field is an infinite homogeneous quantum computer. On a quantum computer the information cannot propagate faster than , and being the minimum space and time distances between gates, respectively. It is shown that the information flow satisfies a Dirac equation, with speed and mass-dependent. For the speed of light is a vacuum refraction index increasing monotonically from to , being the Planck mass for the Planck length.