Geometry-diversified Coulomb excitations in trilayer AAB stacking graphene
arXiv:1807.11776 · doi:10.1103/PhysRevB.98.195442
Abstract
The lower-symmetry trilayer AAB-stacked graphene exhibits rich electronic properties and thus diverse Coulomb excitations. Three pairs of unusual valence and conduction bands create nine available interband excitations for the undoped case, in which the imaginary (real) part of the polarizability shows 1D square root asymmetric peaks and 2D shoulder structures (pairs of antisymmetric peaks and logarithm type symmetric peaks). Moreover, the low frequency acoustic plasmon, being revealed as a prominent peak in the energy loss spectrum, can survive in a narrow gap system with the large-density-of-states from the valence band. This type of plasmon mode is similar to that in a narrow gap carbon nanotube. However, the decisive mechanism governing this plasmon is the intraband conduction state excitations. Its frequency, intensity and critical momentum exhibit a non-monotonic dependence on the Fermi energy. The well-defined electron-hole excitation boundaries and the higher frequency optical plasmons are transformed by varying the Fermi energy. There remain substantial differences between the electronic properties of trilayer AAB, ABC, AAA and ABA graphene stackings.
arXiv comment20 pages, 8 figures. arXiv admin note: text overlap with arXiv:1601.00223 by other authors
References in corpus (6)
- Flat Bands in Slightly Twisted Bilayer Graphene
- Dielectric screening and plasmons in AA-stacked bilayer graphene
- Electronic transition from graphite to graphene via controlled movement of the top layer with scanning tunneling microscopy
- Electrically tunable plasma excitations in AA-stacking multilayer graphene
- Stacking-dependent electronic property of trilayer graphene epitaxially grown on Ru(0001)
- Unusual Coulomb excitations in ABC-stacked trilayer graphene