Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Einstein nanocrystal   We study the simplest possible model of nanocrystal consisting in a simple
cubic lattice with a small number of atoms (NA ~ 10-10^3), where each atom is
linked to its nearest neighbor by a quantum harmonic potential. Some properties
(entropy, temperature, specific heat) of the nanocrystal are calculated
numerically but exactly within the framework of the microcanonical ensemble. We
find that the presence of a surface in the nanocrystal modifies the
thermostatistic properties to a greater extent than the small number of atoms
in the system. The specific heat Cv behaves similarly to the Einstein solid,
with an asymptotic value for high temperatures that differs from that of the
Dulong-Petit law by a term of the order of NA^(-1/3) and that can be explained
easily in terms of the surface. The entropy is non-additive, but this is due to
the presence of the surface and we show that the additivity is recovered in the
thermodynamic limit. Finally, we find that, when calculations follow the
canonical ensemble, results differ little for small systems (NA = 27) and are
inexistent for larger systems (NA = 1000).

6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an