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. High-frequency second sound is demonstrated in bulk natural Ge between 7 K and room temperature by studying the phase lag of the thermal response under a harmonic high-frequency external thermal excitation and addressing the relaxation time and the propagation velocity of the heat waves. These results provide a route to investigate the potential of wave-like heat transport in almost any material, opening opportunities to control heat through its oscillatory nature.
Original language | English |
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Article number | 4677 |
Number of pages | 6 |
Journal | Science advances |
Volume | 7 |
Issue number | 27 |
DOIs | |
Publication status | Published - Jun 2021 |
Keywords
- GERMANIUM
- SEMICONDUCTORS
- SCATTERING
- EQUATION
- HOLES