Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Clausius heat transfer: the example of harmonic chain with an
  impurity   Motivated by recent discussion about the possibility of non-Clausius (from
cold to hot) heat flow, we revisit the familiar model of an impurity atom of
mass $M$ embedded in an otherwise uniform one-dimensional harmonic lattice of
host atoms of mass $m$. Assuming that the initial distributions for the
impurity and the rest of the lattice have canonical forms with given
temperatures, we show that the average kinetic energy of the impurity may
increase with time even if its initial temperature is higher than or equal to
that of the lattice. Such an increase is only temporary in uniform lattices and
in lattices with a heavy impurity ($M\ge m$), but may be permanent in lattices
with a localized vibrational mode generated by a light impurity ($M<m$). Thus
the model shows a non-Clausius spontaneous heat flow directed from a colder
lattice to a hotter impurity.

7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom