Electric control of the heat flux

Manipulating phonons is a complicated task due to their lack of mass or electric charge. Nevertheless, some vibrational modes in polar crystals can be strongly affected by external electric fields. In this work we exploit this idea to propose a thermal transistor based on ferroelectric PbTiO₃. We explore how electric fields with different orientations with respect to the ferroelectric polarization affect the phonon spectrum and thus the lattice thermal conductivity (k_lat) of this compound. We analyse the factors that contribute to the reduction of the lattice thermal conductivity for the different field orientations and find that a reduction of as much as 50% on the k_lat can be achieved at room temperature with experimentally accessible electric fields.

For more details see

Electric control of the heat flux through electrophononic effects, J.A. Seijas-Bellido, H. Aramberri, J.Íñiguez, R. Rurali. Phys. Rev. B 97 184306 (2018) (Also check in the supplementary information available online the hysteretic behaviour we found for k_lat!)

Preprint available in arXiv 1805.08213