High-Threshold Code for Modular Hardware With Asymmetric Noise
Xiaosi Xu, Qi Zhao, Xiao Yuan, Simon C. Benjamin · Physical Review Applied · 2019
Practical, large-scale quantum computers require active error correction, but for this to work the components must attain fidelities that are very challenging. Here the authors customize the leading ``surface code'' approach, layering it on top of a second, simpler code to detect the most common type of noise. Information from the lower-level code is fed into a specialized, advanced controller for the higher-level code so that it can make smarter choices. Numerical simulations confirm that the authors' code is superior over a wide range of parameters, in terms of noise and hardware connectivity. This work offers a potential path to scaling up quantum hardware under biased noise.