  We explore the possibility for translationally invariant quantum many-body
systems to undergo a dynamical glass transition, at which ergodicity and
translational invariance break down spontaneously, driven entirely by quantum
effects. In contrast to analogous classical systems, where the existence of
such an ideal glass transition remains a controversial issue, a genuine phase
transition is predicted in the quantum regime. This ideal quantum glass
transition can be regarded as a many-body localization transition due to
self-generated disorder. Despite their lack of thermalization, these
disorder-free quantum glasses do not possess an extensive set of local
conserved operators, unlike what is conjectured for many-body localized systems
with strong quenched disorder.
