Superconducting quantum computer: a hint for building architectures

We discuss the scalability of superconducting quantum computers, especially in a wiring problem. The number of wiring inside a cryostat is almost proportional to the number of qubits in the current wiring architecture. We introduce "The three-Y's": regularity, modularity, and hierarchy to an architecture design of superconducting quantum computers. The key to the wiring elimination is found in the quantum error correction codes having thresholds and spatial translational symmetry, i.e., the surface code. We show a superconducting-digital-logic-based architecture and introduce a stacked heterogeneous structure of the quantum module.