Lifetime of sub-THz coherent acoustic phonons in a GaAs-AlAs superlattice
We measure the lifetime of the zone-center 340 GHz longitudinal phonon mode in a GaAs-AlAs superlattice excited and probed with femtosecond laser pulses. By comparing measurements conducted at room temperature and liquid nitrogen temperature, we separate the intrinsic (phonon-phonon scattering) and...
| Main Authors: | , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Institute of Physics (AIP)
2013
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| Online Access: | http://hdl.handle.net/1721.1/78357 https://orcid.org/0000-0002-1891-1959 https://orcid.org/0000-0002-3968-8530 https://orcid.org/0000-0001-7804-5418 |
| Summary: | We measure the lifetime of the zone-center 340 GHz longitudinal phonon mode in a GaAs-AlAs superlattice excited and probed with femtosecond laser pulses. By comparing measurements conducted at room temperature and liquid nitrogen temperature, we separate the intrinsic (phonon-phonon scattering) and extrinsic contributions to phonon relaxation. The estimated room temperature intrinsic lifetime of 0.95 ns is compared to available calculations and experimental data for bulk GaAs. We conclude that ∼0.3 THz phonons are in the transition zone between Akhiezer and Landau-Rumer regimes of phonon-phonon relaxation at room temperature. |
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