On the theory side : Are there better QEC schemes less demanding in terms of physical qubits and gates overhead conceivable ?
In this context, many questions are pressing. On the experimental side: Are the experimental error rates really sufficient to implement QEC? What architecture can realistically reach the fault-tolerance level? On the theory side : Are there better QEC schemes less demanding in terms of physical qubits and gates overhead conceivable ? Are QEC schemes resilient to other error models than the simplistic ones? What is the “killer app” for a small-scale quantum computers with typically 50 physical qubits?