Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elasticity of 2D ferroelectrics across their paraelectric phase
  transformation   The mechanical behavior of two-dimensional (2D) materials across 2D phase
changes is unknown, and the finite temperature ($T$) elasticity of paradigmatic
SnSe monolayers -- ferroelectric 2D materials turning paraelectric as their
unit cell (u.c.) turns from a rectangle onto a square -- is described here in a
progressive manner. To begin with, their zero$-T$ {\em elastic energy
landscape} gives way to (Boltzmann-like) averages from which the elastic
behavior is determined. These estimates are complemented with results from the
strain-fluctuation method, which employs the energy landscape or {\em ab
initio} molecular dynamics (MD) data. Both approaches capture the coalescence
of elastic moduli $\langle C_{11}(T)\rangle=\langle C_{22}(T)\rangle$ due to
the structural transformation. The broad evolution and sudden changes of
elastic parameters $\langle C_{11}(T)\rangle$, $\langle C_{22}(T)\rangle$, and
$\langle C_{12}(T)\rangle$ of these atomically-thin phase-change membranes
establishes a heretofore overlooked connection among 2D materials and soft
matter.

8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph