85,856 research outputs found
Tuning electronic structure of graphene via tailoring structure: theoretical study
Electronic structures of graphene sheet with different defective patterns are
investigated, based on the first principles calculations. We find that
defective patterns can tune the electronic structures of the graphene
significantly. Triangle patterns give rise to strongly localized states near
the Fermi level, and hexagonal patterns open up band gaps in the systems. In
addition, rectangular patterns, which feature networks of graphene nanoribbons
with either zigzag or armchair edges, exhibit semiconducting behaviors, where
the band gap has an evident dependence on the width of the nanoribbons. For the
networks of the graphene nanoribbons, some special channels for electronic
transport are predicted.Comment: 5 figures, 6 page
Checking the transverse Ward-Takahashi relation at one loop order in 4-dimensions
Some time ago Takahashi derived so called {\it transverse} relations relating
Green's functions of different orders to complement the well-known
Ward-Green-Takahashi identities of gauge theories by considering wedge rather
than inner products. These transverse relations have the potential to determine
the full fermion-boson vertex in terms of the renormalization functions of the
fermion propagator. He & Yu have given an indicative proof at one-loop level in
4-dimensions. However, their construct involves the 4th rank Levi-Civita tensor
defined only unambiguously in 4-dimensions exactly where the loop integrals
diverge. Consequently, here we explicitly check the proposed transverse
Ward-Takahashi relation holds at one loop order in -dimensions, with
.Comment: 20 pages, 3 figures This version corrects and clarifies the previous
result. This version has been submitted for publicatio
Probing Electroweak Symmetry Breaking Mechanism at the LHC: A Guideline from Power Counting Analysis
We formulate the equivalence theorem as a theoretical criterion for
sensitively probing the electroweak symmetry breaking mechanism, and develop a
precise power counting method for the chiral Lagrangian formulated electroweak
theories. Armed with these, we perform a systematic analysis on the
sensitivities of the scattering processes
and for testing all possible effective bosonic
operators in the chiral Lagrangian formulated electroweak theories at the CERN
Large Hadron Collider (LHC). The analysis shows that these two kinds of
processes are "complementary" in probing the electroweak symmetry breaking
sector.Comment: Extended version, 11-page-Latex-file and 3 separate PS-Figs. To be
Published in Mod.Phys.Lett.
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