Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetization process and magnetocaloric effect in geometrically
  frustrated Ising antiferromagnet and spin ice models on a `Star of David'
  nanocluster   Magnetic and magnetocaloric properties of geometrically frustrated
antiferromagnetic Ising (IA) and ferromagnetic spin ice (SI) models on a
nanocluster with a `Star of David' topology, including next-nearest-neighbor
(NNN) interactions, are studied by an exact enumeration. In an external field
applied in characteristic directions of the respective models, depending on the
NNN interaction sign and magnitude, the ground state magnetization of the IA
model is found to display up to three intermediate plateaus at fractional
values of the saturation magnetization, while the SI model shows only one
zero-magnetization plateau and only for the antiferromagnetic NNN coupling. A
giant magnetocaloric effect is revealed in the the IA model with the NNN
interaction either absent or equal to the nearest-neighbor coupling. The latter
is characterized by abrupt isothermal entropy changes at low temperatures and
infinitely fast adiabatic temperature variations for specific entropy values in
the processes when the magnetic field either vanishes or tends to the critical
values related to the magnetization jumps.

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The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
2
The categories of this paper are: math
18
The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: supr-con
1
The categories of this paper are: cs
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The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci