Dimensional crossover of weak-localization and interaction effects inNb0.53Ti0.47-Ge multilayers

The transport properties of ${\mathrm{Nb}}_{0.53}$ ${\mathrm{Ti}}_{0.47}$-Ge multilayer samples with similar ${\mathrm{Nb}}_{0.53}$ ${\mathrm{Ti}}_{0.47}$ layer thicknesses but varying Ge layer thicknesses were studied. Evidence for a three- to two-dimensional crossover was observed in the temperature and magnetic field dependences of resistance when the Ge layer thickness passes through a critical thickness of ∼ 30 Å, which suggests a strong effect of the barrier width on quantum diffusion processes in disordered multilayer systems.