  The fate of an injected hole in a Mott antiferromagnet is an outstanding
issue of strongly correlated physics. It provides important insights into doped
Mott insulators closely related to high-temperature superconductivity in
cuprates. Here, we report a systematic numerical study based on the density
matrix renormalization group (DMRG). It reveals a remarkable novelty and
surprise for the single hole's motion in otherwise well-understood Mott
insulators. Specifically, we find that the charge of the hole is self-localized
by a novel quantum interference mechanism purely of strong correlation origin,
in contrast to Anderson localization due to disorders. The common belief of
quasiparticle picture is invalidated by the charge localization concomitant
with spin-charge separation: the spin of the doped hole is found to remain a
mobile object. Our findings unveil a new paradigm for doped Mott insulators
that emerges already in the simplest single hole case.
