Magnetic Penetration Depth in a Superconductor

TL;DR

This paper demonstrates that a finite pairing interaction energy range causes a linear temperature dependence of the London magnetic penetration depth in s-wave superconductors at low temperatures.

Contribution

It introduces the concept that a finite pairing interaction energy range $T_d$ leads to a specific linear temperature dependence of the penetration depth in superconductors.

Findings

Linear temperature dependence of $rac{ riangle ext{lambda}}{ ext{lambda}(0)}$ at low T

Dependence expressed as $(T/T_d)(2/ extpi) ext{ln} 2$

Applicable to s-wave pairing superconductors

Abstract

It is shown that the notion of the finite pairing interaction energy range $T_d$ results in a linear temperature dependence of the London magnetic penetration depth $\Delta \lambda / \lambda (0) = (T/T_d)(2/\pi)\ln 2$ at low temperature, in the case of the s-wave pairing state.