Phonon-mediated anisotropic superconductivity in the Y and Lu nickel borocarbides

Abstract

We present scanning tunneling spectroscopy and microscopy measurements at low temperatures in the borocarbide materials RNi2B2C (R=Y, Lu). The characteristic strong coupling structure due to the pairing interaction is unambiguously resolved in the superconducting density of states. It is located at the superconducting gap plus the energy corresponding to a phonon mode identified in previous neutron scattering experiments. These measurements also show that this mode is coupled to the electrons through a highly anisotropic electron-phonon interaction originated by a nesting feature of the Fermi surface. Our experiments, from which we can extract a large electron-phonon coupling parameter lambda (between 0.5 and 0.8), demonstrate that this anisotropic electron-phonon coupling has an essential contribution to the pairing interaction. The tunneling spectra show an anisotropic s-wave superconducting gap function.

arXiv comment5 pages, 3 figures

References in corpus (14)

• CDW, Superconductivity and Anomalous Metallic Behavior in 2D Transition Metal Dichalcogenides
• Upper critical field pecularities of superconducting YNi2B2C and LuNi2B2C
• Distinguishing d-wave from highly anisotropic s-wave superconductors
• Gap Function with Point Nodes in Borocarbide Superconductor YNi_2B_2C
• Gap Renormalization in Dirty Anisotropic Superconductors: Implications for the Order Parameter of the Cuprates
• Nesting properties and anisotropy of the Fermi surface of LuNi${}_2$B${}_2$C
• Highly Anisotropic Gap Function in Borocarbide Superconductor LuNi_2B_2C
• Low Energy Quasiparticle Excitation in the Vortex State of Borocarbide Superconductor YNi_2B_2C
• Effects of gap anisotropy upon the electronic structure around a superconducting vortex
• A study of the superconducting gap in RNi${}_2$B${}_2$C (R = Y, Lu) single crystals by inelastic light scattering
• Microwave Properties of Borocarbide Superconductors LnNi2B2C (Ln = Y, Er, Tm, Ho)
• Tunneling spectroscopy in the magnetic superconductor TmNi2B2C
• Proximity effect and strong coupling superconductivity in nanostructures built with an STM
• Surface effects in multiband superconductors. Application to MgB${}_2$

Cited by in corpus (26)

• FermiSurfer: Fermi-surface viewer providing multiple representation schemes
• Pressure induced effects on the Fermi surface of superconducting 2H-NbSe${}_2$
• Imaging superconducting vortex core and lattice with the scanning tunneling microscope
• On the use of STM superconducting tips at very low temperatures
• The Dependence of the Superconducting Transition Temperature of Organic Molecular Crystals on Intrinsically Non-Magnetic Disorder: a Signature of either Unconventional Superconductivity or Novel Local Magnetic Moment Formation
• Very Low Temperature Tunnelling Spectroscopy in the heavy fermion superconductor PrOs${}_4$Sb${}_{12}$
• Evidence of gap anisotropy in superconducting YNi2B2C using directional point contact spectroscopy
• Pressure dependence of the upper critical field of MgB2 and of YNi2B2C
• Magnetic field dependence of superconducting energy gaps in YNi2B2C: Evidence of multiband superconductivity
• Anisotropic superconducting gaps in YNi${}_2$B${}_2$C: A first-principles investigation
• Local superconducting density of states of ErNi2B2C
• Point Contact Spectroscopy of Superconducting Gap Anisotropy in Nickel Borocarbide Compound LuNi2B2C
• Strongly Anisotropic s-Wave Gaps in Exotic Superconductors
• Theory of anisotropic s-wave superconductivity with point-node like gap minima: analysis of (Y,Lu)Ni_2B_2C
• Distribution of the superconducting gap in an YNi2B2C film studied by point contact spectroscopy
• Superconducting order parameter in nonmagnetic borocarbides RNi${}_2$B${}_2$C (R=Y, Lu) probed by point-contact Andreev reflection spectroscopy
• BCS theory for s+g-wave superconductivity borocarbides Y(Lu)Ni${}_2$B${}_2$C
• Impurity effects on s+g-wave superconductivity in borocarbides Y(Lu)Ni_2B_2C
• Point-contact spectroscopy of the nickel borocarbide superconductor YNi2B2C in the normal and superconducting state
• Direct observation of a Fermi surface and superconducting gap in LuNi2B2C
• Small-angle neutron scattering study of the vortex lattice in superconducting LuNi2B2C
• Large Broadening of the Superconducting Transition by Fluctuations in a 3D Metal at High Magnetic Fields: The MgB${}_2$ case
• Non-collinear order and gapless superconductivity in s-wave magnetic superconductors
• Point-contact spectroscopy of the borocarbide superconductor YNi2B2C
• Point-contact study of the LuNi2B2C borocarbide superconducting film
• Machine-learning Guided Search for Phonon-mediated Superconductivity in Boron and Carbon Compounds