arXiv subjects

P. E. Lammert

Publications and source records attributed to P. E. Lammert.

2 recordsLinked to original sources

arXiv2000

Topological Phases in Graphitic Cones

The electronic structure of graphitic cones exhibits distinctive topological features associated with the apical disclinations. Aharonov-Bohm magnetoconductance oscillations (period Phi_0) are completely absent in rings fabricated from cones with a single pentagonal disclination. Close to the apex, the local density of states changes qualitatively, either developing a cusp which drops to zero at the Fermi energy, or forming a region of nonzero density across the Fermi energy, a local metalization of graphene.

cond-mat.mtrl-sci↗

arXiv1994

Metallic screening and correlation effects in superconducting fullerenes

We consider the frequency dependent Coulomb interaction between electrons in a molecular metal in the limit in which the conduction bandwidth is much less than the plasma frequency, which in turn is much less than intramolecular excitation energies. In particular, we compute the effective interactions at the Fermi energy in alkali-doped C$_{60}$, to second order in the screened interactions. The frequency dependence of the screening substantially reduces the effects of the long-range part of the Coulomb interaction, leading to the possibility of an effective attraction between electrons.

cond-mat↗