Nonlocal effect on the magnetic penetration depth in multigapped superconductors

TL;DR

This paper discusses how nonlocal effects influence the magnetic penetration depth in multigapped superconductors, highlighting the reduction at low fields due to small energy gaps, with estimations compared to experimental data in MgB2.

Contribution

It provides a theoretical discussion and crude estimation of nonlocal effects on penetration depth in multigapped superconductors, relating findings to experimental muSR data in MgB2.

Findings

Nonlocal effects can reduce the magnetic penetration depth at low fields.

Crude estimations align with experimental muSR data in MgB2.

Presence of small energy gaps influences nonlocal behavior.

Abstract

A brief discussion is given on the nonlocal effect in multigapped superconductivity. It is pointed out that the effective magnetic penetration depth at lower external fields may be reduced by the nonlocal effect associated with the presence of small energy gap. A crude estimation of the effect in double gap system is provided and compared with the data obtained by muSR in MgB2.