The tunneling conductance between a superconducting STM tip and an out-of-equilibrium carbon nanotube

Abstract

We calculate the current and differential conductance for the junction between a superconducting (SC) STM tip and a Luttinger liquid (LL). For an infinite single-channel LL, the SC coherence peaks are preserved in the tunneling conductance for interactions weaker than a critical value, while for strong interactions (g <0.38), they disappear and are replaced by cusp-like features. For a finite-size wire in contact with non-interacting leads, we find however that the peaks are restored even for extremely strong interactions. In the presence of a source-drain voltage the peaks/cusps split, and the split is equal to the voltage. At zero temperature, even very strong interactions do not smear the two peaks into a broader one; this implies that the recent experiments of Y.-F. Chen et. al. (Phys. Rev. Lett. 102, 036804 (2009)) do not rule out the existence of strong interactions in carbon nanotubes.

8 pages, 3 figures

References in corpus (14)

• Origin of Spatial Charge Inhomogeneity in Graphene
• Scanning Tunneling Spectroscopy of Graphene on Graphite
• Quasiparticle Chirality in Epitaxial Graphene Probed at the Nanometer Scale
• Transport properties of single channel quantum wires with an impurity: Influence of finite length and temperature on average current and noise
• Non-equilibrium Tunneling Spectroscopy in Carbon Nanotubes
• Tunneling spectroscopy of Luttinger-liquid structures far from equilibrium
• Electron tunneling into a quantum wire in the Fabry-Perot regime
• Oscillatory non-linear conductance of an interacting quantum wire with an impurity
• Tunneling into Nonequilibrium Luttinger Liquid with Impurity
• Superconducting Tunneling Spectroscopy of a Carbon Nanotube Quantum Dot
• Screening of a Luttinger liquid wire by a scanning tunneling microscope tip: I. Spectral properties
• Tunneling into strongly biased Tomonaga-Luttinger liquid
• Screening of a Luttinger liquid wire by a scanning tunneling microscope tip: II. Transport properties
• Out-of-equilibrium transport in a typical multi-terminal setup

Cited by in corpus (6)

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• Spatial Dependence of Electron Interactions in Carbon Nanotubes
• Many-particle correlations in non-equilibrium Luttinger liquid
• Luttinger liquids with multiple Fermi edges: Generalized Fisher-Hartwig conjecture and numerical analysis of Toeplitz determinants