Directed transport and Floquet analysis for a periodically kicked   wavepacket at a quantum resonance
  The dynamics of a kicked quantum mechanical wavepacket at a quantum resonance is studied in the framework of Floquet analysis. It is seen how a directed current can be created out of a homogeneous initial state at certain resonances in an asymmetric potential. The almost periodic parameter dependence of the current is found to be connected with level crossings in the Floquet spectrum. 
Emil Lundh (University of Umea)