Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological edge states in two-gap unitary systems: A transfer matrix
  approach   We construct and investigate a family of two-band unitary systems living on a
cylinder geometry and presenting localized edge states. Using the transfer
matrix formalism, we solve and investigate in details such states in the
thermodynamic limit. Analitycity considerations then suggest the construction
of a family of Riemman surfaces associated to the band structure of the system.
In this picture, the corresponding edge states naturally wind around non
contractile loops, defining by the way a topological invariant associated to
each gap of the system.

24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int