  The concept of non-ergodicity in quantum many body systems can be discussed
in the context of the wave functions of the many body system or as a property
of the dynamical observables, such as time-dependent spin correlators. In the
former approach the non-ergodic delocalized states is defined as the one in
which the wave functions occupy a volume that scales as a non-trivial power of
the full phase space. In this work we study the simplest spin glass model and
find that in the delocalized non-ergodic regime the spin-spin correlators decay
with the characteristic time that scales as non-trivial power of the full
Hilbert space volume. The long time limit of this correlator also scales as a
power of the full Hilbert space volume. We identify this phase with the glass
phase whilst the many body localized phase corresponds to a 'hyperglass' in
which dynamics is practically absent. We discuss the implications of these
finding to quantum information problems.
