Environmental Engineering Reference
In-Depth Information
Figure 1.3
Quantum correction scaling factor (
∂
T
MD
/∂
T
real
)inSiNWs
versus (a) quantum temperature (
T
real
) and (b) classical temperature used
in MD simulation (
T
MD
). The mapping between
T
MD
and
T
real
is shown in
Fig. 1.2.
the decrease of scaling factor, while it results in a small quantum
correction above Debye temperature where quantum effect are
negligible (Debye temperature for Si is 645 K [29]). Therefore,
this phenomenological quantum correction technique can at least
qualitatively
capture the temperature effect on thermal transport
in crystalline solids. However, since this classical-quantum mapping
is done based on the system-level properties (e.g., temperature),
it cannot reproduce the actual quantum-mechanical microscopic
properties (e.g., relaxation time and occupation number) at low
temperature, leading to the discrepancy between MD simulation
with quantum correction and fully quantum-mechanical approach
in the prediction of thermal conductivity below Debye temperature
[16].Besides,althoughbothquantumcorrectionschemes(withand
