  We investigate the full counting statistics (FCS) of spin-conserving and
spin-flip charge transitions in Pauli-spin blockade regime of a GaAs double
quantum dot. A theoretical model is proposed to evaluate all spin-conserving
and spin-flip tunnel rates, and to demonstrate the fundamental relation between
FCS and waiting time distribution. We observe the remarkable features of parity
effect and a tail structure in the constructed FCS, which do not appear in the
Poisson distribution, and are originated from spin degeneracy and coexistence
of slow and fast transitions, respectively. This study is potentially useful
for elucidating the spin-related and other complex transition dynamics in
quantum systems.
