Lifetime of sub-THz coherent acoustic phonons in a GaAs-AlAs superlattice

• Main Authors: Maznev, Alexei (Contributor), Hofmann, Felix (Contributor), Jandl, Adam Christopher (Contributor), Esfarjani, Keivan (Contributor), Bulsara, Mayank (Contributor), Fitzgerald, Eugene A. (Contributor), Chen, Gang (Contributor), Nelson, Keith Adam (Contributor)
• Other Authors: Massachusetts Institute of Technology. Materials Processing Center (Contributor), Massachusetts Institute of Technology. Department of Chemistry (Contributor), Massachusetts Institute of Technology. Department of Materials Science and Engineering (Contributor), Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Massachusetts Institute of Technology. School of Engineering (Contributor)
• Format: Article
• Language: English
• Published: American Institute of Physics (AIP), 2013-04-11T19:32:20Z.
• Subjects: Article
• Online Access: Get fulltext

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.
United States. Dept. of Energy. Office of Basic Energy Sciences (Award DE-SC0001299)
United States. Dept. of Energy (Grant DE-FG02-00ER15087)