When heat goes astray -- non-local heating in a semiconductor
Abstract
Heating of semiconductor devices limits their performance and lifetime, which must be addressed by thermal management starting at the heat source. It is a common assumption that the heat source and the resulting heat spot locally coincide, if their size exceeds the mean free paths of the main heat carriers, the phonons. We show that this paradigm of heat locality breaks down on length scales spanning several micrometers. As a consequence, non-local heating occurs in contradiction to Fourier's law. Therefore, we heat laterally structured semiconductor membranes that feature a rising number of interfaces with a well-focussed laser and map-out lattice temperatures by Raman thermometry. Remarkably, the non-local heating can exceed the laser-induced local heating, which we attribute to ballistic phonon transport far above cryogenic temperatures.
Cite
@article{arxiv.2604.19203,
title = {When heat goes astray -- non-local heating in a semiconductor},
author = {Mahmoud Elhajhasan and Elena Trukhan and Katharina Dudde and Guillaume Würsch and Jana Lierath and Ian Rousseau and Raphaël Butté and Nicolas Grandjean and Nakib Haider Protik and Giuseppe Romano and Gordon Callsen},
journal= {arXiv preprint arXiv:2604.19203},
year = {2026}
}