Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-polarized (001) surface states of the topological crystalline
  insulator Pb_{0.73}Sn_{0.27}Se   We study the nature of (001) surface states in Pb_{0.73}Sn_{0.27}Se in the
newly discovered topological-crystalline-insulator (TCI) phase as well as the
corresponding topologically trivial state above the band-gap-inversion
temperature. Our calculations predict not only metallic surface states with a
nontrivial chiral spin structure for the TCI case, but also nonmetallic
(gapped) surface states with nonzero spin polarization when the system is a
normal insulator. For both phases, angle- and spin-resolved photoelectron
spectroscopy measurements provide conclusive evidence for the formation of
these (001) surface states in Pb_{0.73}Sn_{0.27}Se, as well as for their chiral
spin structure.

20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn