Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconductivity with topological surface state in SrxBi2Se3   By intercalation of alkaline-earth metal Sr in Bi2Se3, superconductivity with
large shielding volume fraction (~91.5% at 0.5 K) has been achieved in
Sr0.065Bi2Se3. The analysis of the Shubnikov-de Hass oscillations confirms the
1/2-shift expected from a Dirac spectrum, giving transport evidence of the
existence of surface states. Importantly, the SrxBi2Se3superconductor is stable
under air, making the SrxBi2Se3 compound an ideal material base for
investigating topological superconductivity.

7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat