Thickness-Dependent Oscillations of the Critical Magnetic Field Induced by the Quantum Size Effect in Superconducting Nanofilms

Abstract

The superconductor to normal metal transition driven by the in-plane magnetic field is investigated for Al nanofilms. Taking the Pauli breaking mechanism (with no orbital effect) into account, it is shown that the critical field oscillates as a function of the nanofilm thickness. This effect is discussed in terms of the quantization of electron energy caused by the confinement of its motion in the direction perpendicular to the film. The analysis of the critical field in the context of Clogston–Chandrasekhar limit is also included.