  Being a very promising technology, with impressive advances in the recent
years, it is still unclear how quantum computing will scale to satisfy the
requirements of its most powerful applications. Although continued progress in
the fabrication and control of qubits is required, quantum computing
scalability will depend as well on a comprehensive architectural design
considering a multi-core approach as an alternative to the traditional
monolithic version, hence including a communications perspective. However, this
goes beyond introducing mere interconnects. Rather, it implies consolidating
the full communications stack in the quantum computer architecture. In this
paper, we propose a double full-stack architecture encompassing quantum
computation and quantum communications, which we use to address the monolithic
versus multi-core question with a structured design methodology. For that, we
revisit the different quantum computing layers to capture and model their
essence by highlighting the open design variables and performance metrics.
Using behavioral models and actual measurements from existing quantum
computers, the results of simulations suggest that multi-core architectures may
effectively unleash the full quantum computer potential.
