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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Generation and Propagation of Superhigh-Frequency Bulk Acoustic Waves in GaAs

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Machado, Diego H. O. [1, 2, 3] ; Crespo-Poveda, Antonio [1] ; Kuznetsov, Alexander S. [1] ; Biermann, Klaus [1] ; Scalvi, Luis V. A. [2, 3] ; Santos, V, Paulo
Total Authors: 6
[1] V, Leibniz Inst Forsch Verbund Berlin eV, Paul Drude Inst Festkorperelekt, Hausvogteipl 5-7, D-10117 Berlin - Germany
[2] Sao Paulo State Univ UNESP, Dept Phys, Sch Sci, Av Eng Luiz Edmundo C Coube 14-01, BR-17033360 Bauru, SP - Brazil
[3] Grad Program Mat Sci & Technol POSMAT, Av Eng Luiz Edmundo C Coube 14-01, BR-17033360 Bauru, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: PHYSICAL REVIEW APPLIED; v. 12, n. 4 OCT 7 2019.
Web of Science Citations: 0

Coherent superhigh-frequency (SHF) vibrations provide an excellent tool for the modulation and control of excitations in semiconductors. Here, we investigate the piezoelectric generation and propagation of longitudinal bulk acoustic waves (LBAWs) with frequencies up to 20 GHz in GaAs crystals using bulk acoustic-wave resonators (BAWRs) based on piezoelectric thin ZnO films. We show that the electroacoustic conversion efficiency of the BAWRs depends sensitively on the sputtering conditions of the ZnO films. The BAWRs are then used for the study of the propagation properties of the LBAWs in GaAs in the frequency and temperature ranges from 1 to 20 GHz and 10 and 300 K, respectively, which have so far not been experimentally accessed. We find that the acoustic absorption of GaAs in the temperature range from 80 K to 300 K is dominated by scattering with thermal phonons. In contrast, at lower temperatures, the acoustic absorption saturates at a frequency-dependent value. Experiments carried out with different propagation lengths indicate that the saturation is associated with losses during reflections at the sample boundaries. We also demonstrate devices with a high quality factor fabricated on top of acoustic Bragg reflectors. The results presented here prove the feasibility of high-quality acoustic resonators embedding GaAs-based nanostructures, thus opening the way for the modulation and control of their properties by electrically excited SHF LBAWs. (AU)

FAPESP's process: 17/24311-6 - Piezoelectric excitation of GHz vibrations in GaAs-based structures
Grantee:Diego Henrique de Oliveira Machado
Support Opportunities: Scholarships abroad - Research Internship - Doctorate