A regular computer can already represent i. You can do complex math on them fine, it's just a matter of specifying what the bits mean and the rules they follow.

A regular computer can already represent i. You can do complex math on them fine, it's just a matter of specifying what the bits mean and the rules they follow. I don't think that has anything to do with quantum or not, and I'm not sure what there is to "solve" about the sqrt(-1). We know what it is, it's just called i in the complex numbers (by definition). There's not another level to go down and explore. (in some other number systems, like the reals, sqrt(-1) just doesn't exist because no number times itself is -1).