  The design of Quantum Turbo Codes (QTCs) typically relies on the analysis of
their distance spectra, followed by Monte-Carlo simulations. By contrast, in
this paper we appropriately adapt the conventional non-binary EXtrinsic
Information Transfer (EXIT) charts for quantum turbo codes by exploiting the
intrinsic quantum-to-classical isomorphism. The EXIT chart analysis not only
allows us to dispense with the time-consuming Monte-Carlo simulations, but also
facilitates the design of near-capacity codes without resorting to the analysis
of their distance spectra. We have demonstrated that our EXIT chart predictions
are in line with the Monte-Carlo simulations results. We have also optimized
the entanglement-assisted QTC using EXIT charts, which outperforms the existing
distance spectra based QTCs. More explicitly, the performance of our optimized
QTC is as close as 0.3 dB to the corresponding hashing bound.
