Coherence of polaronic transport in layered metals
  Layered systems shows anisotropic transport properties. The interlayer conductivity show a general temperature dependence for a wide class of materials. This can be understood if conduction occurs in two different channels activated at different temperatures. We show that the characteristic temperature dependence can be explained using a polaron model for the transport. The results show an intuitive interpretation in terms of coherent and incoherent quasi-particles within the layers. Further, we extract results for the magnetoresistance, thermopower, spectral function and optical conductivity for the model and discuss application to experiments. 
Urban Lundin and Ross H. McKenzie