  Transport through spin-blockaded quantum dots provides a means for electrical
control and detection of nuclear spin dynamics in the host material. Although
such experiments have become increasingly popular in recent years,
interpretation of their results in terms of the underlying nuclear spin
dynamics remains challenging. Here we point out a fundamental process in which
nuclear spin dynamics can be driven by electron shot noise; fast electric
current fluctuations generate much slower nuclear polarization dynamics, which
in turn affect electron dynamics via the Overhauser field. The resulting
extremely slow intermittent current fluctuations account for a variety of
observed phenomena that were not previously understood.
