Condensation Energy for a Two-Gap Superconducting State in Nanoparticles

Abstract EN

Recent technology and experiments have fabricated high-quality superconducting MgB2 nanoparticles.

We investigate properties of two-gap superconductivity in nanosized systems by using a two-sublevel model.

In the present work, we analyze the results obtained for superconducting granules in the case of multiband superconductivity.

We discuss the finite size effect in multiband superconductors.

A definition of the critical level spacing of two-gap superconductivity is also presented, and we discuss the condensation energy and the parity gap of two-gap superconductivity in relation to the size dependence of those properties with two bulk gaps and the effective pair scattering process between two sublevels.