12–17 Jun 2016
University of Ottawa
America/Toronto timezone
Welcome to the 2016 CAP Congress! / Bienvenue au congrès de l'ACP 2016!

Gapless superconductivity on the surface of a 3D topological insulator

15 Jun 2016, 09:15
15m
SITE G0103 (University of Ottawa)

SITE G0103

University of Ottawa

Oral (Non-Student) / orale (non-étudiant) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) W1-1 Superconductivity (DCMMP) / Supraconductivité (DPMCM)

Speaker

isil ozfidan (University of Alberta)

Description

Recent angle-resolved photoemission experiments have observed a proximity-induced superconducting gap in the helical surface states of the 3D topological insulator Bi$_2$Se$_3$, when a thin film of the latter is grown on a superconducting NbSe$_2$ substrate. The superconducting coherence peaks are strongly suppressed when the topological insulator thin film is doped with magnetic Mn impurities, which was interpreted as a destruction of superconductivity in the topological surface states. Motivated by these experiments, we explore a different possibility: gapless superconductivity, where a gapless electronic density of states coexists with a nonzero superconducting order parameter. We study a model of superconducting Dirac fermions coupled to random magnetic impurities within the Abrikosov-Gor'kov framework, and find finite regions of gapless superconductivity in the phase diagram of the system for both proximity-induced and intrinsic superconductivity.

Primary authors

Jinsen Han (University of Alberta) Joseph Maciejko (University of Alberta) isil ozfidan (University of Alberta)

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