Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Green's Function Method for Line Defects and Gapless Modes in
  Topological Insulators : Beyond Semiclassical Approach   Defects which appear in heterostructure junctions involving topological
insulators are sources of gapless modes governing the low energy properties of
the systems, as recently elucidated by Teo and Kane [Physical Review B82,
115120 (2010)]. A standard approach for the calculation of topological
invariants associated with defects is to deal with the spatial inhomogeneity
raised by defects within a semiclassical approximation. In this paper, we
propose a full quantum formulation for the topological invariants
characterizing line defects in three-dimensional insulators with no symmetry by
using the Green's function method. On the basis of the full quantum treatment,
we demonstrate the existence of a nontrivial topological invariant in the
topological insulator-ferromagnet tri-junction systems, for which a
semiclassical approximation fails to describe the topological phase. Also, our
approach enables us to study effects of electron-electron interactions and
impurity scattering on topological insulators with spatial inhomogeneity which
gives rise to the Axion electrodynamics responses.

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The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys