Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

8-1-2016

Journal or Book Title

Physical Review B

Volume

94

Issue

6

First Page

064521

DOI

10.1103/PhysRevB.94.064521

Abstract

A highly anisotropic superconducting gap is found in single crystals of FeSe by studying the London penetration depth Δλ 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 Tc increases by 0.4 K from Tc0≈8.8 K while the structural transition temperature Ts decreases by 0.9 K from Ts0≈91.2 K after electron irradiation. We discuss several explanations for the Tc enhancement and propose that local strengthening of the pair interaction by irradiation-induced Frenkel defects most likely explains the phenomenon.

Comments

This article is published as Teknowijoyo, S., K. Cho, M. A. Tanatar, J. Gonzales, A. E. Böhmer, O. Cavani, V. Mishra, P. J. Hirschfeld, S. L. Bud’ko, P. C. Canfield, and R. Prozorov. "Enhancement of superconducting transition temperature by pointlike disorder and anisotropic energy gap in FeSe single crystals." Physical Review B 94, no. 6 (2016): 064521. DOI: 10.1103/PhysRevB.94.064521. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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