Design automation challenges for scalable quantum architectures

Building a quantum computer that is sufficiently large for solving classically intractable computational problem instances is a grand challenge of today´s science. The main fundamental obstacle to construction of scalable quantum computers is the vulnerability of their extremely fragile components to noise and decoherence due to environment interaction. This paper focuses on design of technology-independent quantum circuit architectures that are scalable and reliable as well as well-suited for physical implementation. The considered architectures will be protected against errors by state-of-the-art topological quantum error-correcting (TQEC) codes which combine a number of properties enabling the best scalability among all discussed alternatives. The theory of TQEC is very mature, the suitable hardware has made significant progress in recent years, and therefore the software challenges constitute the research gaps. We explain the abstraction levels which lay the foundation for systematic, top-down design automation methods for TQEC computers, discuss the appropriate optimization objectives and formulate a number of largely open design automation problems in this fields.