[atomack]

I'd say that's more a mathematical statement than physical derivation. The effort of subjects like string theory is to lay down fundamental objects and interactions from which other theories (quantum mechanics, gravity) emerge. But I don't think there is a final word at the moment of what the fundamental theories than result in quantum mechanics should look like.

[gus_massa]

In string theory, they use quantum (super)strings, not classic strings that somehow simulate quantum particles. It's quantum all the way down.