title: Electrical manipulation of crystal symmetry for switching transverse acoustic phonons.
abstract: We experimentally explore the use of a novel device where lateral electric fields can be applied to break the translational symmetry within the isotropic plane and hence change the selection rules to allow normally forbidden transverse acoustic (TA) phonon generations. The ultrafast screening of the lateral electric field by the photocarriers relieves shear strain in the structure and switches on the propagating TA waves. The amplitude and on-state time of the TA mode can be modulated by the external field strength and size of the laterally biased region. The observed frequency shift with an external bias as well as the strong geometrical dependence confirm the role of the asymmetric potential distribution in electrically manipulating the crystal symmetry to control modal behavior of acoustic phonons.
authors: School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
authors: H
authors: H
authors: Jeong
authors: School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
authors: Y D
authors: YD
authors: Jho
authors: Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
authors: C J
authors: CJ
authors: Stanton