Lorentz violating effects on a quantized two-level system
  In this work, we consider the effects of the Lorentz-violating (LV) term $ v_{\mu}\bar{\psi}\gamma ^{\mu}\psi $ belonging to the fermion sector of the extended standard model on the dynamics of a quantum two-level system. We examine how its non-relativistic counterpart, ${(\mathbf{p}-e \mathbf{A})\cdot }\mathbf{v}/{m_{e},}$ affects the Rabi oscillations of a two-level atom coupled with a quantum cavity electromagnetic field. Taking an initial coherent field state in a resonant cavity, it was found that the LV background increases the Rabi frequency and the time interval between collapses and revivals of the population inversion function. It was found that initial field states with low mean number of photons are better probes in order to establish more stringent upper bounds on the background magnitude. In particular, for an initial vacuum state in the cavity the upper limit $\text{v}_{x}<10^{-10}eV$ was attained. 
M. M. Ferreira Jr. (UFMA), A.R. Gomes (CEFET-Ma)