| Summary: | 博士 === 國立清華大學 === 物理研究所 === 81 === In this thesis, we studied many-body effects in two graphite-
related systems: graphite intercalation compounds (GIC''s) and
graphene tubules. Both of the systems are made of graphite
sheets, and atoms or moleculars could be intercalated into them
to enhance the carrier density but without modifying the honey
comb structure of the graphite layers. Owing to these
similarities, we could build up our theory for the systems by
employing the unique band structure of a single graphite sheet.
Very different symmetries of the two structures, however, make
them behave differently. GIC''s are made of periodically staked
graphite layers; as a result, the system could exhibit rich
one-, two-, and three-dimensional properties. For GIC''s, we
have studied their screening behaviors, transport properties,
self-energy correction, and excitonic effects. A graphene
tubule is a rolled-up graphite sheet in a cylindrical form with
a diameter in the nanometers. Due to the microscopic structure,
graphene tubules have novel one- and two-dimensional physical
properties. In this work, we studied elementary excitations,
magnetoplasmons and persistent currents, and self-energy
correction of the graphene tubules. During the studies, we have
paid special attention to compare the many-body theory with the
experiments, and have predicted some novel features which have
yet to be verified experimentally. The results of this research
clearly illustrate that the many-body effects are fundamental
to the understanding of the important physical properties of
these two systems.
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