https://doi.org/10.1140/epjb/e2002-00367-6
On-site repulsion as the source of pairing in carbon nanotubes and intercalated graphite
Istituto Nazionale per la Fisica della Materia,
Dipartimento di Fisica, Universita' di Roma Tor Vergata, Via della Ricerca Scientifica, 1-00133 Roma, Italy
Corresponding author: a cini@roma2.infn.it
Received:
13
July
2002
Published online:
29
November
2002
We show that different non-conventional superconductors have
one fundamental feature in common: pair eigenstates of the
Hamiltonian are repulsion-free, the W=0 pairs. In
extended Hubbard models, pairing can occur for reasonable
parameter values. For (N,N) nanotubes the binding
energy of the pair depends strongly on the filling and decreases
towards a reduced but nonzero value for the graphite sheet 
.
PACS: 74.20.Mn – Nonconventional mechanisms (spin fluctuations, polarons and bipolarons, resonating valence bond model, anyon mechanism, marginal Fermi liquid, Luttinger liquid, etc.) / 73.22.-f – Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 73.63.Fg – Nanotubes
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002
