NMR relaxation time in a clean two-band superconductor

TL;DR

This paper investigates the nuclear magnetic resonance spin-lattice relaxation rate in a clean two-band superconductor, considering various pairing symmetries and emphasizing inter-band interference effects, using a generalized Eliashberg theory.

Contribution

It introduces a comprehensive analysis of NMR relaxation in two-band superconductors with arbitrary pairing symmetries, highlighting inter-band effects and extending Eliashberg theory.

Findings

Inter-band interference significantly affects relaxation rates.

Conventional isotropic gaps analyzed with two-band Eliashberg theory.

Results applicable to both conventional and unconventional pairing symmetries.

Abstract

We study the spin-lattice relaxation rate of nuclear magnetic resonance in a two-band superconductor. Both conventional and unconventional pairing symmetries for an arbitrary band structure in the clean limit are considered. The importance of the inter-band interference effects is emphasized. The calculations in the conventional case with two isotropic gaps are performed using a two-band generalization of Eliashberg theory.