  Optical control strategies in semiconductor nanostructures have almost
exclusively relied on heavy-hole exciton and trion states. In the first part of
this letter, we show that light-hole trions provide the missing ressource for
consolidating all single qubit operations in a mutually compatible magnetic
field configuration: electron spin initialization and control can be achieved
through light-hole trion states and cycling transition is provided by
heavy-hole trion states. In the second part, we experimentally demonstrate that
pairs of nitrogen atoms in GaAs exhibiting a Cs symmetry bind both light- and
heavy-hole excitons and negative trions. A detailed analysis of the fine
structure reveals that that trion states provide the lambda level structure
necessary for fast initialization and control along with
energetically-protected cycling transition compatible with single-shot readout.
