Direct observation of two-phonon bound states in ZnTe
arXiv:1011.6115 · doi:10.1103/PhysRevB.84.224304
Abstract
A coherent two-phonon bound state has been impulsively generated in ZnTe(110) via second-order Raman scattering in the time domain for the first time. The two-phonon bound state, composed of two anticorrelated in wave vector acoustic phonons, exhibits full Γ1 symmetry and has energy higher than the corresponding 2TA(X) overtone. By suppressing two-phonon fluctuations with a double-pulse excitation, the coexistence of coherently excited bound and unbound two-phonon states has been demonstrated.
14 pages, 4 figures, This paper is accepted for publication in Phys. Rev. B