  When ultrafast laser pulse strikes the crystal with a van Hove singularity in
the phonon density of states, it can create a pair of anti-correlated in
wave-vector acoustic phonons. As a result, the atomic fluctuations in either
position or momentum become squeezed in such a way that their size might fall
below the vacuum level. The ultrafast pulses can also generate a two-phonon
bound (biphonon) state in which the constituent phonons are correlated and/or
entangled. Here we show that via the interplay between one- and two-phonon
interference the bound and squeezed two-phonon state in (110) oriented ZnTe
single crystal can be manipulated. We demonstrate experimentally that when two
biphonon ensembles are temporally and spatially overlapped, the strength of
phonon squeezing and correlation can be controlled. However, due to the
complementarity of one- and two-phonon interference a larger correlation comes
at the expense of a reduced squeezing.
