Observation of second sound in a rapidly varying temperature field in Ge
Abstract
Second sound is known as the thermal transport regime where heat is carried by temperature waves. Its experimental observation was previously restricted to a small number of materials, usually in rather narrow temperature windows. We show that it is possible to overcome these limitations by driving the system with a rapidly varying temperature field. This effect is demonstrated in bulk Ge between 7 kelvin and room temperature, studying the phase lag of the thermal response under a harmonic high frequency external thermal excitation, addressing the relaxation time and the propagation velocity of the heat waves. These results provide a new route to investigate the potential of wave-like heat transport in almost any material, opening opportunities to control heat through its oscillatory nature.
Keywords
Cite
@article{arxiv.2007.05487,
title = {Observation of second sound in a rapidly varying temperature field in Ge},
author = {Albert Beardo and Miquel López-Suárez and Luis Alberto Pérez and Lluc Sendra and Maria Isabel Alonso and Claudio Melis and Javier Bafaluy and Juan Camacho and Luciano Colombo and Riccardo Rurali and F. X. Alvarez and Juan Sebastián Reparaz},
journal= {arXiv preprint arXiv:2007.05487},
year = {2021}
}
Comments
After careful revision we have ruled out the presence of coherent noise and from any other noise source within the reported data. We have updated the manuscript providing a detailed analysis of the photoreflectance signal, demonstrating with experiments its thermal origin