  Given a quantum state at some instant of time t, the underlying system
Hamiltonian can not only predict how the state will evolve, but also the
history of the state prior to t. Thereby, in order to have a directed motion,
like in a diode, some sort of irreversibility must be considered. For the atom
diode, this has been achieved by spontaneous decay of excited atomic levels.
For an atomic condensate, it is clear, however, that such decay will cause both
heating and decoherence of the condensate. To overcome this complication we
introduce a different setup where the dissipation does not act directly on the
atoms. The excited atoms are stimulatedly driven back to the ground state by
exciting a cavity mode, which in return decays to the vacuum via photon losses.
The efficiency of the method utilizing experimental parameters is shown to be
almost perfect within large parameter regimes.
