Superconducting proximity effect in topological metals

Abstract

Much interest in the superconducting proximity effect in three-dimensional (3D) topological insulators (TIs) has been driven by the potential to induce Majorana bound states at the interface. Most candidate materials for 3D TI, however, are bulk metals, with bulk states at the Fermi level coexisting with well-defined surface states exhibiting spin-momentum locking. In such topological metals, the proximity effect can differ qualitatively from that in TIs. By studying a model topological metal-superconductor (TM-SC) heterostructure within the Bogoliubov-de Gennes formalism, we show that the pair amplitude reaches the naked surface, unlike in a topological insulator-superconductor (TI-SC) heterostructure where it is confined to the interface. Furthermore, we predict vortex-bound-state spectra to contain a Majorana zero-mode localized at the naked surface, separated from the bulk vortex-bound-state spectra by a finite energy gap in such a TM-SC heterostructure. These naked-surface-bound modes are amenable to experimental observation and manipulation, presenting advantages of TM-SC over TI-SC.

7 pages, 3 figures

References in corpus (13)

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• Absence of a Proximity Effect in a Topological Insulator on a Cuprate Superconductor: Bi2Se3/Bi2Sr2CaCu2O8
• Effects of surface-bulk hybridization in 3D topological `metals'
• Disordered topological metals

Cited by in corpus (12)

• Anomalous Josephson effect in d-wave superconductor junctions on TI surface
• Induced spectral gap and pairing correlations from superconducting proximity effect
• Superconducting proximity effect in a topological insulator using Fe(Te,Se)
• Realizing Majorana Zero Modes by Proximity Effect between Topological Insulators and d-wave High-Temperature Superconductors
• Topological orders competing for the Dirac surface state in FeSeTe surfaces
• Controversy over large proximity induced s wave like pairing from a d wave superconductor
• Coulomb Blockade Effects in a Topological Insulator Grown on a High-Tc Cuprate Superconductor
• Superconducting-contact-induced resistance-anomalies in the 3D topological insulator Bi2Te3
• Hard and soft x-ray photoemission spectroscopy study of the new Kondo system SmO thin film
• Proximity effect in a heterostructure of a high $T_c$ superconductor with a topological insulator from Dynamical mean field theory
• Phase Thermalization: from Fermi Liquid to Incoherent Metal
• Proximity-Induced Superconductivity in a Topological Crystalline Insulator