The origin of the condensation energy scaling of iron-based superconductors. (12th August 2016)

• Record Type: Journal Article
• Authors: Bang, Yunkyu
• Is Part Of: Europhysics letters. Volume 115:Number 2(2016:Jul.)
• Publication Date: 2016-08-12
• Subjects: 74.20.-z -- 74.25.Bt -- 74.70.Xa; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/115/27002
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: The relation between the condensation energy (CE) and T c of a phase transition reveals a fundamental nature of the transition. In view of this, the recent experimental observation of the non-BCS scaling relation of the CE vs. with about forty different samples of the Fe-based superconductors (Xing J. et al., Phys. Rev. B, 89 (2014) 140503) was intriguing and strongly hinted at a non-BCS pairing mechanism. In this paper, we have studied the CE and T c of the multiband BCS model and found that the observed anomalous scaling relation is well reproduced by the two-band BCS model paired by a dominant repulsive interband interaction . Our result implies that this seemingly non-BCS–like scaling behavior of, on the contrary to the common expectations, is in fact a strong experimental evidence that the pairing mechanism of the Fe-based superconductors is genuinely a BCS mechanism, meaning that the Cooper pairs are formed by the itinerant carriers glued by a pairing interaction .