Quasiparticle Properties of an Electron Gas in a Cylindrical Tubule

Abstract

The self-energy of an electron gas confined to a cylindrical tubule is studied within the dynamic random phase approximation. As a result of the cylindrical symmetry, each subband is described by the angular momentum (l), and the excitation spectrum by the transferred angular momentum (L) of the Coulomb interactions. All of the intrasubband (L=0) and intersubband (L≠ 0) interactions are included in the self-energy. Quasiparticle energy and energy width exhibit the multiple divergent structures, mainly owing to the various plasmons. The contributions due to the ± L intersubband plasmons are the same for the l=0 subband, but not the same for the l≠ 0 subbands. Hence, there are more divergent structures in the self-energies of the l≠ 0 subbands. The downshift of subband edge strongly depends on the carrier density, the tubular radius, and the effective mass. It exhibits cusps or jumps at certain carrier densities, where the subband crossings occur. The special jumps are related to a new L=0 plasmon.