I'm not a quantum physicist, but I pretend that copious amounts of reading and watching PBS Space Time and Infinite has made me somewhat knowledgeable on this.

I'm not a quantum physicist, but I pretend that copious amounts of reading and watching PBS Space Time and Infinite has made me somewhat knowledgeable on this. The author looks to have previously been a theoretical physicist, so I might be very off base here, but... this thread doesn't square up with my understanding of things at all. >QUANTUM INTERFERENCE IS JUST WHAT QUANTUM PROCESSORS DO, ITS A BUG, NOT A FEATURE This sort of throws the whole series of tweets into question for me. Of course interference is a feature - you want to create a pattern of interference where paths leading to the wrong answer interfere with each other and cancel out! Without interference I don't understand how quantum computers could even work, what they would look like, and why we would want to use them for anything. >which, to me, is an infuriating thing to label “quantum supremacy” because quantum interference is EXACTLY WHY WE CAN’T USE CURRENT QUANTUM PROCESSORS TO “BREAK ALL CRYPTO” IN THE FIRST PLACE BECAUSE WE CANNOT DO EFFICIENT QUANTUM ERROR CORRECTING CODES Error correction requires more qubits to do the error correction. We need the current qubits just to do the calculations, leaving us no qubits to use for error correction. Quantum interference certainly isn't the reason we can't do error correction. If the author is confusing decoherence and interference, then I can understand why they believe what they do, though that confusion ultimately removes a significant portion of their point. Decoherence is what takes something in superposition and puts it back into the realm of classical physics - we lose the ability to utilize that quantum interference and entangled qubits. Ultimately to get a result we have to de-cohere the qubit, because we have to observe it, so not all decoherence is bad. The problem is all sorts of things besides our desired observation can cause decoherence, which results in errors, and avoiding this requires implementing error correction, which takes additional physical qubits. We need a lot more physical qubits, qubits that are more resistant to decohering when we don't want them to, and/or for someone to come through with a breakthrough that does error correcting much more efficiently than the methods Shor came up with. Of course, I might be the one that's confused here.