Molecular Dynamics Simulations for Computing Thermal Conductivity of Nanomaterials - Nanoscale Energy Transport and Harvesting - page 13

Figure 1.2 Classical temperature used in MD simulation ( T MD )versus
quantum temperature for the real environment ( T real ) in SiNWs. The solid
anddottedlinedraws T MD withoutandwithzero-pointenergy,respectively.
Thedashedlinedraws T real for reference.

As a result, the mapping between T MD and T real is not unique but
depends on the exactdefinition of the systemenergy.
The quantum correction to the thermal conductivity is a post-
processing step after MD simulation. By assuming the heat flux is
equal inthe classical and quantumsystems
J =− κ MD ∇ T MD =− κ real ∇ T real ,

(1.32)

thermal conductivity isrescaled by quantumcorrection as
κ real = κ MD ∂ T MD

∂ T real ,

(1.33)

with a scaling factor ∂ T MD
∂

T real which can be calculated from Eq. 1.30 or

1.31.
Figure 1.3 shows the typical quantum correction scaling factor
in SiNWs derived from the temperature mapping shown in Fig. 1.2.
With quantum correction, it can qualitatively take into account the
decreaseofheatcapacityincrystallinesolidsatlow-temperatureby