  We herein report a new class of impulsive fractional stochastic differential
systems driven by mixed fractional Brownian motions with infinite delay and
Hurst parameter $\hat{\cal H} \in ( 1/2, 1)$. Using fixed point techniques, a
$q$-resolvent family, and fractional calculus, we discuss the existence of a
piecewise continuous mild solution for the proposed system. Moreover, under
appropriate conditions, we investigate the approximate controllability of the
considered system. Finally, the main results are demonstrated with an
illustrative example.
