QUANTUM TRANSPORT IN PTSI THIN-FILMS AND NARROW WIRES

The low-temperature magnetoresistance (MR) of PtSi thin films and narrow wires with 6 nm thickness has been studied to determine the physical parameters in the weak localization with strong spin-orbit interaction, including superconducting fluctuations. We find the magnetic scattering to be negligible in the thin films. For the wires, the obtained magnetic scattering time tau(s) is found to decrease with narrowing wire width. This is interpreted as the spin effect due to sidewall damage caused by ion-beam etching. The reduction in T-c with narrowing width has also been deduced, which is qualitatively explained both by the increase of localization which enhances the Coulomb interaction and by the increased magnetic scattering which destroys Cooper pairs.