  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 {\Gamma}1 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.
