Observing the Berry phase in diffusive conductors : necessary conditions for adiabaticity

We investigate Berry phase effects in the magnetoconductance of diffusive systems, and determine the precise criterion for adiabaticity within the weak-localization formalism. We show that the exact solution of the Cooperon propagator for the special case of a cylindrically symmetric texture agrees with the adiabatic approximation in the adiabatic limit characterized by tau much greater than(1/d)(l(2)/L-2). We point out that orientational inhomogeneities in the magnetic field induce dephasing effects that can mask the Berry phase (and any other phase-coherent phenomena) for certain parameter values of system and field.