We report on electrically modulating and switching the wavy properties of acoustic phonons in nanoscale piezoelectric heterostructures which are strained both from the pseudomorphic growth at the interfaces as well as through external electric fields. In symmetry planes of such structures, the generation and detection of the transverse acoustic modes are forbidden, and only longitudinal acoustic phonons are generated by ultrafast displacive screening of strains. We show that the combined application of lateral and vertical electric fields can not only turn on and off various modes but they can also modulate the amplitudes and frequencies of the modes [1-3]. The role of the electrical controllability of phonons was further demonstrated as changes to the propagation velocities; the electrically polarized TA waves; and the geometrically varying optical sensitivities of phonons. The capability to manipulate the phononic functionalities with electric fields is analogous to that for manipulating photons and electrons in major technological devices and can be a practical route for integrated phononic circuitry. [1] C. S. Kim et al., Appl. Phys. Lett. 100, 101105 (2012). [2] H. Jeong et al., Phys. Rev. Lett. 114, 043603 (2015). [3] H. Jeong et al., Phys. Rev. B (to appear).

Date Published: 28 April 2017
PDF: 1 pages
Proc. SPIE 10112, Photonic and Phononic Properties of Engineered Nanostructures VII, 101121V (28 April 2017); doi: 10.1117/12.2251320

Published in SPIE Proceedings Vol. 10112:
Photonic and Phononic Properties of Engineered Nanostructures VII
Ali Adibi; Shawn-Yu Lin; Axel Scherer, Editor(s)