What happened to Voldemort's wand after the last book, and does Harry own it now?

What happened to Voldemort's wand after the last book, and does Harry own
it now?

Is there any reference about what happened to Voldemort's wand after he
started using the Elder Wand he stole from Hogwarts? Would it stop
responding to Voldemort after he started using the elder wand? This does
not seem a possibility, as he never really mastered the Elder Wand.
However, now that Harry has defeated him in a duel, does his original wand
change alliance as well as the Elder Wand? Does Harry own 4 wands at the
end of the Book (his own, Elder Wand, Draco's and Voldemort's) ?