Robust Odd-Parity Superconductivity in the Doped Topological Insulator NbₓBi₂Se₃

Author

M. P. Smylie
K. Willa
H. Claus
A. Snezhko
I. Martin
W.-K. Kwok
Y. Qiu
Yew San Hor, Missouri University of Science and TechnologyFollow
E. Bokari
P. Niraula
A. Kayani
V. Mishra
U. Welp

Abstract

We present resistivity and magnetization measurements on proton-irradiated crystals demonstrating that the superconducting state in the doped topological insulator Nb_xBi₂Se₃ (x=0.25) is surprisingly robust against disorder-induced electron scattering. The superconducting transition temperature T_C 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 E_u pairing state in this material.

Recommended Citation

M. P. Smylie and K. Willa and H. Claus and A. Snezhko and I. Martin and W. Kwok and Y. Qiu and Y. S. Hor and E. Bokari and P. Niraula and A. Kayani and V. Mishra and U. Welp, "Robust Odd-Parity Superconductivity in the Doped Topological Insulator NbₓBi₂Se₃," Physical Review B, vol. 96, no. 11, American Physical Society (APS), Sep 2017.

The definitive version is available at https://doi.org/10.1103/PhysRevB.96.115145

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.

Publication Date

01 Sep 2017