  Trapping ultracold atoms in optical lattices enabled numerous breakthroughs
uniting several disciplines. Coupling these systems to quantized light leads to
a plethora of new phenomena and has opened up a new field of study. Here we
introduce a physically novel source of competition in a many-body strongly
correlated system: We prove that quantum backaction of global measurement is
able to efficiently compete with intrinsic short-range dynamics of an atomic
system. The competition becomes possible due to the ability to change the
spatial profile of a global measurement at a microscopic scale comparable to
the lattice period without the need of single site addressing. In coherence
with a general physical concept, where new competitions typically lead to new
phenomena, we demonstrate novel nontrivial dynamical effects such as
large-scale multimode oscillations, long-range entanglement and correlated
tunneling, as well as selective suppression and enhancement of dynamical
processes beyond the projective limit of the quantum Zeno effect. We
demonstrate both the break-up and protection of strongly interacting fermion
pairs by measurement. Such a quantum optical approach introduces into many-body
physics novel processes, objects, and methods of quantum engineering, including
the design of many-body entangled environments for open systems.
