Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tuning lattice thermal conductance by porosity control in ultra-scaled
  Si and Ge nanowires   Porous nanowires (NWs) with tunable thermal conductance are examined as a
candidate for thermoelectric (TE) devices with high efficiency (ZT). Thermal
conductance of porous Si and Ge NWs is calculated using the complete phonon
dispersion obtained from a modified valence force field (MVFF) model. The
presence of holes in the wires break the crystal symmetry which leads to the
reduction in ballistic thermal conductance ($\sigma_{l}$). $[100]$ Si and Ge
NWs show similar percentage reduction in $\sigma_{l}$ for the same amount of
porosity. A 4nm $\times$ 4nm Si (Ge) NW shows $\sim$ 30% (29%) reduction in
$\sigma_{l}$ for a hole of radius 0.8nm. The model predicts an anisotropic
reduction in $\sigma_{l}$ in SiNWs, with $[111]$ showing maximum reduction
followed by $[100]$ and $[110]$ for a similar hole radius. The reduction in
$\sigma_{l}$ is attributed to phonon localization and anisotropic mode
reduction.

32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio