Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface antiferromagnetism and incipient metal-insulator transition in
  strained manganite films   Using first-principles calculations, we show that the (001) surface of the
ferromagnet La$_{1-x}$Sr$_{x}$MnO$_{3}$ under epitaxial compression favors
antiferromagnetic ordering in the first few surface layers, coexisting with
ferromagnetic bulk order. The change in magnetic order is accompanied by a
marked surface-related spectral pseudogap, signaling a metal-insulator
near-transition at the surface. All surfaces exhibit huge outward relaxations
an rumpling of the MnO$_{2}$ and LaO surface planes, causing a distinct shift
in work function. The AF phase is an extreme surface-assisted case of the
combination of in-plane AF super-exchange and vertical FM double-exchange
couplings that rules magnetism in manganites under in-plane compression.

14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ