  SGRs/AXPs are assumed to be a class of neutron stars (NS) powered by magnetic
energy and not by rotation, as normal radio pulsars. However, the recent
discovery of radio-pulsed emission in four of this class of sources, where the
spin-down rotational energy lost $\dot{E}_{\rm rot}$ is larger than the X-ray
luminosity $L_X$ during the quiescent state - as in normal pulsars - opens the
question of the nature of these radio AXPs in comparison to the others of this
class. In this work, we show that the radio AXPs obey a linear log-log relation
between $L_X$ and $\dot{E}_{\rm rot}$, very similar to the one of normal X-ray
pulsars, a correlation not seen for the others SGRs/AXPs. This result suggests
a different nature between the radio AXPs comparing to the others SGRs/AXPs.
