PHASE COHERENT LENGTH MEASUREMENTS IN SINGLE-CRYSTAL NISI2 FILMS

The phase coherent length lφ of conduction electrons in single-crystal NiSi2 films has been measured using weak localization phenomena. Logarithmic temperature dependence and logarithmic magnetic-field dependence of the conductivity observed in epitaxially grown NiSi2 single-crystal films with thicknesses from 6 to 40 nm are interpreted in terms of the two-dimensional weak localization with strong spin-orbit interaction. Considerably long-phase coherent lengths are obtained by fitting analyses using magnetoconductance data; lφ=0.8 μm at 4.2 K and 1.5 μm at 2 K. This is due to a very low concentration of magnetic scatterers in NiSi 2. Because of its long-phase coherent length, the single-crystal NiSi2 film can be applied to novel quantum interference devices.