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arXiv · 2007.05487

Observation of second sound in a rapidly varying temperature field in Ge

Albert Beardo·Miquel López-Suárez·Luis Alberto Pérez·Lluc Sendra·Maria Isabel Alonso·Claudio Melis·Javier Bafaluy·Juan Camacho·Luciano Colombo·Riccardo Rurali·F. X. Alvarez·Juan Sebastián Reparaz
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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.

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Albert Beardo, Miquel López-Suárez, Luis Alberto Pérez, Lluc Sendra, Maria Isabel Alonso, Claudio Melis, Javier Bafaluy, Juan Camacho, Luciano Colombo, Riccardo Rurali, F. X. Alvarez, Juan Sebastián Reparaz. 2020-07-10. Observation of second sound in a rapidly varying temperature field in Ge. https://arxiv.org/abs/2007.05487

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