A delta-kicked model for the quantum ratchet effect

• A delta-kicked model is proposed for the quantum ratchet effect.
• Two symmetrical flashing potentials alternately act on a particle.
• Temporal symmetry is destroyed while spatial symmetry is preserved in our model.
• Ratchet currents emerge when quantum resonances are excited.
• Some characteristics of our model are investigated.

We construct a delta-kicked model for the quantum ratchet effect. Two symmetric flashing potentials alternately act on a particle with a symmetric and homogeneous initial state of zero momentum. Ratchet currents emerge when quantum resonances are excited. We give some results and compare our model and a previous model. Our work provides a way to control the quantum transport of cold atoms experimentally.