STUDY OF KINETIC FRICTION OF SOLID USING DRIVEN LATTICE OF QUANTIZED VORTEX IN HIGH-TEMPERATURE SUPERCONDUCTORS–A NEW ROUTE TO STUDY SOLID-SOLID FRICTION

Abstract

We show that quantized magnetic vortex lattice in high-temperature cuprate superconductors driven by dc or ac current is a very good model system for investigating physics of friction of solid. Based on the dc I-V characteristic measurement and viscosity measurement using microwave techniques in Bi 2 Sr 2 CaCu 2 O y and La 1.85 Sr 0.15 CuO 4, the corresponding kinetic friction was obtained as functions of temperature, magnetic field and driving current density. With increasing magnetic field and temperature, velocity dependence of kinetic friction behaves as that at interfaces with weak interaction of solid. This result means that we can control the kinetic friction, and that systematic experiments are available in a reproducible manner with using this system. Behavior of the kinetic friction at higher velocities (~1 km/s) agrees well with a two-class potential model at finite temperatures. Irradiation of the columnar defects was found to move the system closer to the so-called Amontons-Coulomb friction. This suggests that the random potential created by the strong pinning centers plays an important role of the validity of Amontons-Coulomb law.