Quantum computers are computers that hold a bunch of information. Now, These quantum computers need to grow to be able to mine bitcoin. The only problem with a quantum computer is that it is way slower than normal computers so you would need a lot of quantum computers to make the same computing power as a normal computer. The only problem with opening up these quantum computers is that they are way more prone to hacking than other computers. These are why quantum computers should not be able to mine bitcoin.