There's a concept in quantum mechanics known as entanglement, whereby acting upon one particle of an entangled pair changes the other. (That's not entirely accurate from a real world science perspective, but it's close enough for science fiction/fantasy.)
That could be used to explain things like Sending Stones.
Another interesting aspect of quantum mechanics is the concept of superposition, where a particle can be in multiple states at once until it is observed (and thereby falls out of superposition). This is most famously illustrated in the Schrodinger's Cat thought experiment. In short, you put a cat in a box. The box contains poison gas that is triggered by the decay of a radioactive element. The cat, standing in for a particle in superposition, is both alive and dead until observed, at which point it falls out of superposition and is either alive or dead. (Multiverse explanations then go on to state that if the cat died in this universe, it survived in another universe [and if it died in our universe, it survived in another universe]).
That could be used to explain any number of magical effects.
Finally there is quantum teleportation whereby quantum particles can travel from point A to point C without passing through the intervening point B.
While it doesn't really work that way in our universe, this could explain teleportation effects. Technically speaking, according to my extremely layman's understanding of quantum mechanics, a person teleporting via quantum teleportation could hypothetically happen, but the odds of it happening within the lifespan of our universe are infinitesimally miniscule.