First principles simulation of the non-linear Peltier effect*

When matter is subject to large electric fields or temperature gradients, the usual linear approximations for the transportation of charge and heat, Ohm's and Fourier's law, break down. This gives rise to non-linear transport phenomena like negative-differential conduction.

We have developed a method based on real-time electron dynamics to simulate non-linear conduction from first principles. Our approach was first implemented for electrical conduction. We now extend the method to account for non-linear thermal conduction, using a quantum theory of heat based on real-time time dependent density functional theory (TDDFT).

In this talk we present our initial results for the simulation of the non-linear heat transport effects for hydrogren at a high-pressure metallic phase. By applying a strong electric field to the material and following in real time the induced heat current, we can predict the non-linear Peltier coefficient for the material.

The results of these simulations will help us understand when non-linear conduction effects appear and when they are important to understand the behavior of matter under extreme conditions.