  Although individual spins in quantum dots have been studied extensively as
qubits, their investigation under strong resonant driving in the scope of
accessing Mollow physics is still an open question. Here, we have grown high
quality positively charged quantum dots embedded in a planar microcavity that
enable enhanced light-matter interactions. Under a strong magnetic field in the
Voigt configuration, individual positively charged quantum dots provide a
double-lambda level structure. Using a combination of above-band and resonant
excitation, we observe the formation of Mollow triplets on all optical
transitions. We find that when the strong resonant drive power is used to tune
the Mollow triplet lines through each other, we observe anticrossings. We also
demonstrate that the interaction that gives rise to the anticrossings can be
controlled in strength by tuning the polarization of the resonant laser drive.
Quantum-optical modeling of our system fully captures the experimentally
observed spectra and provides insight on the complicated level structure that
results from the strong driving of the double-lambda system.
