Nano-Scale heat conduction

talimutalimu Member Posts: 8

Hi Support team,

We know that Heat conduction in macrostructures is typically treated as a diffusion process governed by Fourier law:

where q is the local heat flux and DT the temperature gradient, k is the thermal conductivity of the material that is temperature-dependent.

However, in nanoscale, this behavior is highly questionable.

So, how does Lumerical calculate its thermal conduction in nanoscale devices? Do you use some specific model? If so, please elaborate on it.

Let's say I use HEAT solver, for simulating a changes in index of refraction along the nanoscale device due to heat source located on the other side. So in this case, how the temperature distribution is calculated along the nanoscale device, according to what model?




  • gsungsun Posts: 729Ansys Employee

    Thank you to bring this interesting topic!

    HEAT solver solves the heat transportation equations for bulk materials. I have not seen similar equations for micro- or nano- scale devices. What people do is to modify the material properties in order to get accurate result. Some heat parameters can be as large/small as 30% of the bulk materials. So it is up to the end users to give "correct" material properties, which can be very challenge.

    A few years ago, a group of scholars from Zhejiang University (led by Dr. Qiu min) published a paper discussing the heat effect in nano scale, and suggest to significantly modify the material's heat parameters. Please search online and find some related information.

  • talimutalimu Posts: 28Member

    Hi gsun,

    Thank you for the info, I will look it up.

    So, what you are saying essentially, that Lumerical refers to heat transportation in nanoscale devices as heat transportation equations for bulk materials. Namely, there is no special model for nanoscale devices, and the accuracy is only up to defining new materials with updated parameters?

    Thanks in Advance,


  • gsungsun Posts: 729Ansys Employee

    I did not find any special model for nano scale devices, except to modify the thermal parameters of the materials involved. Please refer Dr.Qiu's paper.

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