Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Odd-frequency superconductivity and Meissner effect in the doped
  topological insulator Bi$_2$Se$_3$   Doped Bi$_2$Se$_3$ is proposed to be a nematic superconductor originating
from unusual inter-orbital pairing. We classify all induced superconducting
pair correlations in Bi$_2$Se$_3$ and discover that intra-orbital odd-frequency
pairing dominates over a significant range of frequencies. Moreover, we explore
the contributions of even- and odd-frequency pairing to the Meissner effect,
including separating intra- and inter-band processes in the response function.
Contrary to expectations, and due to inter-band contributions, we find a
diamagnetic odd-frequency Meissner effect.

13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom