Quantum Computer systems will need to spend a lot of time on error correction

The IARPA Quantum Computer Science (QCS) Program explores questions relating to the computational resources required to run quantum algorithms on realistic quantum computers.

Any implementation of a quantum algorithm requires not only programming the algorithm at a logical level but also the incorporation of error correction and control schemes at the physical level, and resource estimation must account for all of these factors. The QCS program is developing a tool chain to study these issues throughout the computing process.

The tools will include an integrated development environment for the quantum programming languages already developed by the program, compilers to generate logical circuits, and tools for analyzing quantum error correction and control protocols. Through its research QCS will build a foundation for measuring and reducing the resources required to program and implement complex quantum algorithms of realistic size.”

Theoretical claims have largely ignored overhead associated with instantiation of algorithms by realistic physical systems.
• QCS looked at annotated algorithms, that is, all of the quantum operations required to implement an algorithm
including control, housekeeping, and error correction
• In the absence of such actual systems, QCS posited PMDs that, albeit idealized, will approximate best case performance
• QCS parameterized PMDs so as to be able to look at a range of error correction techniques and algorithms