We study the temperature dependence of the conductivity due to quantum
interference processes for a two-dimensional disordered itinerant electron
system close to a ferromagnetic quantum critical point. Near the quantum
critical point, the cross-over between diffusive and ballistic regimes of
quantum interference effects occurs at a temperature T∗=1/τγ(EFτ)2, where γ is the parameter associated with the Landau
damping of the spin fluctuations, τ is the impurity scattering time, and
EF is the Fermi energy. For a generic choice of parameters, T∗ is
smaller than the nominal crossover scale 1/τ. In the ballistic quantum
critical regime, the conductivity behaves as T1/3.Comment: 5 pages, 1 figur