Phonon-dominated energy transport in purely metallic heterostructures
We use ultrafast x-ray diffraction to quantify the transport of energy in laser-excited nanoscale Au/Ni bilayers. Electron transport and efficient electron-phonon coupling in Ni convert the laser-deposited energy in the conduction electrons within a few picoseconds into a strong non-equilibrium betw...
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Published in | arXiv.org |
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Main Authors | , , , , , , , |
Format | Paper |
Language | English |
Published |
Ithaca
Cornell University Library, arXiv.org
05.04.2022
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Subjects | |
Online Access | Get full text |
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Summary: | We use ultrafast x-ray diffraction to quantify the transport of energy in laser-excited nanoscale Au/Ni bilayers. Electron transport and efficient electron-phonon coupling in Ni convert the laser-deposited energy in the conduction electrons within a few picoseconds into a strong non-equilibrium between hot Ni and cold Au phonons at the bilayer interface. Modeling of the subsequent equilibration dynamics within various two-temperature models confirms that for ultrathin Au films the thermal transport is dominated by phonons instead of conduction electrons because of the weak electron-phonon coupling in Au. |
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ISSN: | 2331-8422 |