The superconducting gaps in LiFeAs: Joint study of specific heat and ARPES

TL;DR

This study combines specific heat and ARPES measurements to analyze the superconducting gaps in LiFeAs, revealing two distinct s-wave gaps consistent across both methods, advancing understanding of its superconducting properties.

Contribution

It provides a joint experimental analysis of specific heat and ARPES data to identify and confirm two superconducting energy gaps in LiFeAs, highlighting their magnitudes and agreement between techniques.

Findings

Two s-type energy gaps with magnitudes of approximately 1.2 meV and 2.6 meV.

Superconducting transition shows a pronounced anomaly in specific heat.

Excellent agreement between specific heat and ARPES results.

Abstract

We present specific heat, c_P, and ARPES data on single crystals of the stoichiometric superconductor LiFeAs. A pronounced anomaly is found in c_P at the superconducting transition. The electronic contribution can be described by two s-type energy gaps with magnitudes of approximately Delta1 = 1.2 meV and Delta2 = 2.6 meV and a normal-state gamma coefficient of 10 mJ/mol K^2. All these values are in remarkable agreement with ARPES results.