Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Robust topological insulator surface state in MBE grown
  (Bi_{1-x}Sb_x)_2Se_3   (Bi1-xSbx)2Se3 thin films have been prepared using molecular beam epitaxy
(MBE). We demonstrate the angle-resolved photoemission spectroscopy (ARPES) and
transport evidence for the existence of strong and robust topological surface
states in this ternary system. Large tunability in transport properties by
varying the Sb doping level has also been observed, where insulating phase
could be achieved at x=0.5. Our results reveal the potential of this system for
the study of tunable topological insulator and metal-insulator transition based
device physics.

3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int