Surface effect on transport properties in HTSC

The critical transport current due to surface barriers is found for high-temperature superconductors and shown to decrease as 1/H for large magnetic fields. A self-consistent problem of the current distribution between the flux ''entry'' and ''exit'' surfaces is solved. The surface contribution is proved to be not affected by thermal fluctuations of vortex lines. Thus the surface effects on the transport properties are especially important at high-temperatures where the bulk pinning is reduced by temperature. (orig.)