Superconductivity induced by inter-band nesting in the three-dimensional honeycomb lattice

Abstract

In order to study whether the inter-band nesting can favor superconductivity arising from electron-electron repulsion in a three-dimensional system, we have looked at the repulsive Hubbard model on a stack of honeycomb (i.e., non-Bravais) lattices with the FLEX method, partly motivated by the superconductivity observed in MgB2. By systematically changing the shape of Fermi surface with varied band filling n and the third-direction hopping, we have found that the pair scattering across the two-bands is indeed found to give rise to gap functions that change sign across the bands and behave as an s- or d-wave within each band. This implies (a) the electron repulsion can assist gapful pairing when a phonon-mechanism pairing exists, and (b) the electron repulsion alone, when strong enough, can give rise to a d-wave-like pairing, which should be, for a group-theoretic reason, a time-reversal broken d+id with point nodes in the gap.

References in corpus (14)

• Superconductivity of metallic boron in MgB_2
• Boron Isotope Effect in Superconducting MgB${}_2$
• Evidence for two superconducting energy gaps in MgB2 by point-contact spectroscopy
• Specific Heat of Mg ^{11}B_2
• Specific heat in the superconducting and normal state (2-300 K, 0-16 Teslas), and magnetic susceptibility of the 38-K superconductor MgB2: evidence for a multicomponent gap
• The reduced total isotope effect and its implications on the nature of superconductivity in MgB2
• Evidence for Two Superconducting Gaps in $Mg{B}_2$
• Direct evidence for a multiple superconducting gap in MgB2 from high-resolution photoemission spectroscopy
• Scanning Tunneling Spectroscopy in MgB2
• Exponential Temperature Dependence of Penetration Depth in Single Crystal MgB_2
• High-Resolution Photoemission Study of MgB2
• Possible high $T_c$ superconductivity mediated by antiferromagnetic spin fluctuations in systems with Fermi surface pockets
• Antiferromagnetism of the Hubbard Model on a Layered Honeycomb Lattice - Is MgB${}_2$ a Nearly-Antiferromagnetic Metal? -
• Two-Band-Type Superconducting Instability in MgB2

Cited by in corpus (7)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Phase diagram and magnetic collective excitations of the Hubbard model in graphene sheets and layers
• Proximity and Josephson effects in microstructures based on multiband superconductors
• Superconductivity in repulsive electron systems having three-dimensional disconnected Fermi surfaces
• No superconductivity in Pb${}_9$Cu${}_1$(PO${}_4$)${}_6$O found in orbital and spin fluctuation exchange calculations
• Doping fingerprints of spin and lattice fluctuations in moiré superlattice systems
• Relativistic Model of two-band Superconductivity in (2+1)-dimension