Practical large-scale quantum computers require active error correction, but for this to work, the components must reach fidelities that are very challenging. In this theory paper, we customise the leading ‘surface code’ approach, layering it on top of a second simpler code to detect the most common noise type. Information from the lower code is fed into a customized, advanced controller for the high-level code so that it makes smarter choices. Numerical simulations confirm the new code is superior over a wide range of parameters in terms of the noise and the connectivity of the hardware. The work offers a potential path for scaling up general quantum hardware with biased noise.
For more details please refer to our paper on arXiv: https://arxiv.org/abs/1812.01505
