Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum magnetoelectric effect in molecular crystal Dy$_3$   Magnetoelectric properties of a molecular crystal formed by dysprosium
triangular clusters are investigated. The effective spin-electric Hamiltonian
is derived on the base of developed quantum mechanical model of the cluster
spin structure. The magnetoelectric contribution to the free energy of the
crystal is calculated. The analysis reveals several distinctive features of the
magnetoelectric effect, which are not typical for conventional paramagnetic
systems at low temperatures. The peculiarities are explained by the chirality
of the dysprosium core of the molecules.

36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio