Quanta Magazine: A New Approach to Multiplication Opens the Door to Better Quantum Computers

But the same feature that makes quantum computers powerful makes them fragile. Because the qubits are entangled, you can’t change a few of them without affecting all the others. That makes it impossible to selectively erase information the way a classical computer can. Tossing away qubits is like snipping strands in a spider’s web — even a single snip can unravel the whole thing.