electron thermal conductivity during 2T state

[Serj-R]

Hi,

After femtosecond laser excitation of metals is it assumed that the electronic thermal conductivity (k_el) varies in the way: k_el = k_0*(Te/Ti), where k_0 - is the initial electronic thermal conductivity, Te - electronic temperature, Ti - lattice temperature.

I tried to modify this parameter in the code in the way: k_el_Au = lambda Te, Ti: (Te/Ti)317u.W/(u.m*u.K); #Heat conductivity But an error occurs, am I doing somethin wrong or the code does not support such modification?

Only one parameter dependence works: k_el_Au = lambda Te: (Te/300)317u.W/(u.mu.K); #Heat conductivity But in this case the Ti always equals only to 300 K (initial temperature of lattice), however the lattice normally heats up during the first several ps.

[VaSca92]

Hi Serj, I did not know these type of model was used. In the current version of the code, the conductivity of a given system only depends on the temperature of the same system. I am afraid you can not simulate the model you need.

Luckyly, I am currently working on an update of the code and I would like to upload it in the second half of June. The update will surely include this feature.

Please, let me know more about the model you need to simulate:

• Is this "multiple dependence" used also in 3 temperature model? Does the conductivity depends also on the spin temperature?
• Is this used also for the specific heat? May it depend on other systems temperatures too?

Please, notify us any issue or success of the code in reproducing experimental data, as this is fundamental for implementation of future updates.

Thank you for using our code :)

[Serj-R]

Hi Valentino!

This is great, give me some time and I will let you know what dependences should be simulated.

In our experiments (time-domain thermoreflectance or transient thermoreflectance) we cannot measure directly the temperatures of electrons and phonons, but we can measure the time dependence of optical properties (reflectance) which depend, in particular, on temperatures of electrons and phonons. To reproduce the optical measurements beside the calculation of the coupled differential equations with correctly chosen dependences we also need to implement the appropriate optical model (Drude, for example), that is why there could be several areas of errors.

But surely, I will notify you in case of success. Without doubt.

[Serj-R]

Hello,

For example, in the attached file in the APPENDIX B: THERMAL CONDUCTIVITY OF Ni AND Au UNDER CONDITIONS OF ELECTRON-LATTICE NONEQUILIBRIUM you will find several dependences of electron conductivity during 2T state on the temperatures of electrons and lattice for Au. I think, the equation (B1) is the most frequently used one for Au. You can see that electron conductivity always depends both on Te and Ti, but this dependence significantly changes with increasing Te. So for Au, in the temperature range of electrons 330 - 15000K one should use the dependence (B1). The shown graphs of course are valid only for Ti = 300 K, with increasing Ti the electron conductivity depndence will change, so all this is discribed by the B1 equation.

Therefore, the possibility to model the electron conductivity dependence on Te and Ti (B1-equation in the paper) in your code would be very very helpful.

PRB03_meltNiAu.pdf