Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermal rectification and negative differential thermal conductance in
  harmonic chains with nonlinear system-bath coupling   Thermal rectification and negative differential thermal conductance were
realized in harmonic chains in this work. We used the generalized
Caldeira-Leggett model to study the heat flow. In contrast to the most previous
studies considering only the linear system-bath coupling, we considered the
nonlinear system-bath coupling based on recent experiment [A. Eichler \emph{et
al.}, Nat. Nanotech. \textbf{6}, 339 (2011)]. When the linear coupling constant
is weak, the multiphonon processes induced by the nonlinear coupling allow more
phonons transport across the system-bath interface and hence the heat current
is enhanced. Consequently, thermal rectification and negative differential
thermal conductance are achieved when the nonlinear couplings are asymmetric.
However, when the linear coupling constant is strong, the umklapp processes
dominate the multiphonon processes. Nonlinear coupling suppresses the heat
current. Thermal rectification is also achieved. But the direction of
rectification is reversed comparing to the results of weak linear coupling
constant.

29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess