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