“Can antibiotics heal an infected root canal?”

Maybe. Root canal infections are in 3 categories: Infection was never completely abolished during procedure or with initial round of antibiotics. In this case, good chance of resolution. Second, root canal gets infected some years after procedure. In this case, maybe, but good chance root canal will need to be redone. Last, root canal never heals after second or third round of antibiotics. This can be true either at initial treatment or on down the road. Root may be fractured, or cyst may have formed, in which case, extraction or surgical intervention is needed. So, it depends!

Temporarily, but issue will recur unless definitive treatment is instituted.

Probably at least temporarily. In my experience, there is probably something else going on which requires a procedure such as retreatment, apicoectomy, or extraction.

If root canal treatment has been done then possibly, yes.