Circuit-level protocol and analysis for twist-based lattice surgery

Lattice surgery is a measurement-based technique for performing fault-tolerant quantum computation in two dimensions. When using the surface code, most general lattice operations require irregularities called twist defects. However, implementing twist-based may additional resources, such as extra device connectivity, and could lower threshold overall performance code. Here we provide an explicit protocol its requisite connectivity layout. We also new stabilizer measurement circuits measuring defects which are compatible with our chosen gate scheduling. undertake first circuit-level error correction simulations during biased depolarizing noise model. Our results indicate slight decrease timelike logical failures compared to protocols no bulk. comfortably below (i.e. CNOT infidelities $5 \times 10^{-3}$), degradation mild fact preferable over proposed alternative twist-free schemes. Lastly, efficient scheme $Y$ operators along boundaries of codes bypasses certain steps that were required previous