On the dephasing time of the chiral metal
In the low-dimensional disordered systems the dephasing time and the inelastic scattering (out-scattering) time are in general different. We show that in the case of the two-dimensional chiral metal which is formed at the surface of a layered three dimensional system, which is exhibiting the integer quantum Hall effect these two quantities are essentially the same and their temperature-dependence is T^(-3/2). In particular we show that the results obtained using the diagramatic technique and the phase uncertainty approach introduced by A. Stern et al. (Phys. Rev. A 41, 3436 (1990)) for the out-scattering and the dephasing time respectively, coincide. We furthermore consider these quantities in the case of the three-dimensional chiral metal, where similar conclusions are reached.