Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of the topological edge state in X-ray band   The possibility of obtaining robust edge state of light by mimicking the
topological properties of solid state system, have brought a profound impact on
optical sciences. With the advent of high-brilliance, accelerator-driven light
sources such as storage rings or X-ray lasers, it has become attractive to
extend the concept of optical topological manipulation to the X-ray regime. In
this paper, we theoretically proposed and experimentally demonstrated the
topological edge state at the interface of two photonic crystals having
different band-gap topological characteristics for X-ray. Remarkably, this
topologically protected edge state is immune to the weak disorder in form of
the thickness disorder and strong disorder in form of the positional disorder
of layers in the structure, as long as the zero-average-effective-mass
condition is satisfied. Our investigation therefore brings the topological
characteristics to the X-ray regime, provides new theoretical tools to study
X-ray optics and may pave way to exploit some important potential applications,
such as the high efficiency band filter in X-ray band.

25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con