Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological Aspects of Surface States in Semiconductors   Topological aspects of surface states in semiconductors are studied by an
adiabatic deformation which connects a realistic system and a decoupled
covalent-bond model. Two topological invariants are focused. One is a quantized
Berry phase, and the other is a number of the edge states. A winding number as
another topological invariant is also considered. The surface states of Si and
Ge at (111), (110), and (100) surfaces are classified by the topological
invariants. Surface states of the GaAs as heterosemiconductors are also
discussed.

31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org