You are here

Enhancement of superconducting transition temperature by pointlike disorder and anisotropic energy gap in FeSe single crystals

TitleEnhancement of superconducting transition temperature by pointlike disorder and anisotropic energy gap in FeSe single crystals
Publication TypeJournal Article
Year of Publication2016
AuthorsTeknowijoyo, S, Cho, K, Tanatar, MA, Gonzales, J, Bohmer, AE, Cavani, O, Mishra, V, Hirschfeld, PJ, Bud'ko, SL, Canfield, PC, Prozorov, R
JournalPhysical Review B
Volume94
Pagination064521
Date Published08
Type of ArticleArticle
ISBN Number2469-9950
Accession NumberWOS:000382027700009
Keywordschalcogenides, field, instability, iron pnictides, nematicity, penetration depth, phase, physics, state, symmetry
Abstract

A highly anisotropic superconducting gap is found in single crystals of FeSe by studying the London penetration depth Delta lambda measured down to 50 mK in samples before and after 2.5 MeV electron irradiation. The gap minimum increases with introduced pointlike disorder, indicating the absence of symmetry-imposed nodes. Surprisingly, the superconducting transition temperature T-c increases by 0.4 K from T-c0 approximate to 8.8 K while the structural transition temperature T-s decreases by 0.9 K from T-s0 approximate to 91.2 K after electron irradiation. We discuss several explanations for the T-c enhancement and propose that local strengthening of the pair interaction by irradiation-induced Frenkel defects most likely explains the phenomenon.

DOI10.1103/PhysRevB.94.064521
Custom 1

Complex States

Alternate JournalPhys. Rev. B