Abstract

We present resistivity and magnetization measurements on proton-irradiated crystals demonstrating that the superconducting state in the doped topological insulator NbxBi2Se3 (x=0.25) is surprisingly robust against disorder-induced electron scattering. The superconducting transition temperature TC decreases without indication of saturation with increasing defect concentration, and the corresponding scattering rates far surpass expectations based on conventional theory. The low-temperature variation of the London penetration depth Δλ(T) follows a power law [Δλ(T)T2] indicating the presence of symmetry-protected point nodes. Our results are consistent with the proposed robust nematic Eu pairing state in this material.

Department(s)

Physics

Comments

Y.S.H. acknowledges support from the National Science Foundation Grant No. DMR-1255607.

Keywords and Phrases

Impurities in Superconductors; Spin-Triplet Pairing; Topological Superconductors

International Standard Serial Number (ISSN)

2469-9950; 2469-9969

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2017 American Physical Society (APS), All rights reserved.

Included in

Physics Commons

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