  We study coherent oscillations in double quantum dots tunnel-coupled to
metallic leads by means of full counting statistics of electron transport. If
two such systems are coupled by Coulomb interaction, there are in total six
(instead of only two) oscillation modes of the entangled system with
interaction-dependent oscillation frequencies. By tuning the bias voltage, one
can engineer decoherence such that only one of the six modes, in which the
charge oscillations in both double quantum dots become synchronized in
antiphase, is singled out. We suggest to use waiting-time distributions and the
$g^{(2)}$-correlation function to detect the common frequency and the phase
locking.
