Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Born effective charge removed anomalous temperature dependence of
  lattice thermal conductivity in monolayer GeC   Due to potential applications in nano- and opto-electronics, two-dimensional
(2D) materials have attracted tremendous interest. Their thermal transport
properties are closely related to the performance of 2D materials-based
devices. Here, the phonon transports of monolayer GeC with a perfect planar
hexagonal honeycomb structure are investigated by solving the linearized phonon
Boltzmann equation within the single-mode relaxation time approximation (RTA).
Without inclusion of Born effective charges ($Z^*$) and dielectric constants
($\varepsilon$), the lattice thermal conductivity ($\kappa_L$) almost decreases
linearly above 350 K, deviating from the usual $\kappa_L$$\sim$$1/T$ law. The
underlying mechanism is because the contribution to $\kappa_L$ from
high-frequency optical phonon modes increases with increasing temperature, and
the contribution exceeds one from acoustic branches at high temperature. These
can be understood by huge phonon band gap caused by large difference in atom
mass between Ge and C atoms, which produces important effects on scattering
process involving high-frequency optical phonon. When considering $Z^*$ and
$\varepsilon$, the phonon group velocities and phonon lifetimes of
high-frequency optical phonon modes are obviously reduced with respect to ones
without $Z^*$ and $\varepsilon$. The reduced group velocities and phonon
lifetimes give rise to small contribution to $\kappa_L$ from high-frequency
optical phonon modes, which produces the the traditional $\kappa_L$$\sim$$1/T$
relation in monolayer GeC. Calculated results show that the isotope scattering
can also reduce anomalous temperature dependence of $\kappa_L$ in monolayer
GeC. Our works highlight the importance of $Z^*$ and $\varepsilon$ to
investigate phonon transports of monolayer GeC.

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The categories of this paper are: nucl-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: cs
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The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: math
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The categories of this paper are: patt-sol
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an