Comment by smurda

5 years ago I was at MIT’s QC lab and 4 qubits was the max number of entangled qubits their machine could reach, sustainably. All the marketing fluff from IBM and Google about hundreds, or thousands, of entangled qubits is misleading - they don’t maintain those entangled states for long durations. Only when we can get hundreds of qubits to maintain entangled states for sustainable periods of time can we then attempt the theoretical use cases of the technology.