Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface magnetism of gallium arsenide nanofilms   Gallium arsenide (GaAs) is the widest used second generation semiconductor
with a direct band gap and increasingly used as nanofilms. However, the
magnetic properties of GaAs nanofilms have never been studied. Here we find by
comprehensive density functional theory calculations that GaAs nanofilms
cleaved along the <111> and <100> directions become intrinsically metallic
films with strong surface magnetism and magnetoelectric (ME) effect. The
surface magnetism and electrical conductivity are realized via a combined
effect of transferring charge induced by spontaneous electric-polarization
through the film thickness and spin-polarized surface states. The surface
magnetism of <111> nanofilms can be significantly and linearly tuned by
vertically applied electric field, endowing the nanofilms unexpectedly high ME
coefficients, which are tens of times higher than those of ferromagnetic metals
and transition metal oxides.

19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph