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 $\tau \gg {\mathrm{}(1/d)(l}^2{/L}^2).\mathrm{}$ 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.

• Received 22 May 1998

DOI:https://doi.org/10.1103/PhysRevB.59.13328