Velocity-force characteristics of a driven interface in a disordered medium

Article

关键词: CHARGE-DENSITY WAVES;    DEPINNING TRANSITION;    ELASTIC THEORY;    FLUX-CREEP;    DYNAMICS;    SYSTEMS;    SUPERCONDUCTIVITY;    FLUCTUATIONS;    TEMPERATURE;    EXPANSION;   

DOI  :  10.1103/PhysRevB.63.184305

来源: SCIE

【 摘 要 】

Using a dynamic functional renormalization group treatment of driven elastic interfaces in a disordered medium, we investigate several aspects of the creep-type motion induced by external forces below the depinning threshold f(c). (i) We show that in the experimentally important regime of forces slightly below f(c), the velocity obeys an Arrhenius-type law v similar to exp[- U(f)/T] with an effective energy barrier U(f) proportional to (f(c)-f) vanishing linearly when f approaches the threshold f(c). (ii) Thermal fluctuations soften the pinning landscape at high temperatures. Determining the corresponding velocity-force characteristics at low driving forces for internal dimensions d = 1,2 (strings and interfaces) we find a particular non-Arrhenius-type creep v similar to exp[-(f(c)(T)/f)(mu)] involving the reduced threshold force f(c)(T) alone. For d = 3 we obtain a similar v-f characteristic, which is, however, nonuniversal and depends explicitly on the microscopic cutoff.

【 授权许可】

Free