Entry facet
Use cases & realizations
Where the code fits and what has been demonstrated.
Use cases & fit
Platforms: all-to-all-small-register superconducting-small-register trapped-ion-all-to-all
Tasks: error-detection postselected-computation known-erasure-recovery magic-state-preparation
Physical realizations
five-qubit trapped-ion register demonstrated
Four data ions plus an ancilla demonstrated fault-tolerant preparation, syndrome extraction, and logical operations for one protected logical qubit. The second encoded degree of freedom was treated as a gauge qubit, so the experiment is not evidence that both logical qubits were protected by the same protocol.
References: linke2017faulttolerant
five-qubit superconducting transmon register demonstrated
Fault-tolerant state preparation was demonstrated in a protected one-logical-qubit subspace of the block. This protocol-specific subsystem use is narrower than arbitrary two-logical-qubit fault tolerance.
References: takita2017experimental
IBM five-qubit superconducting processors demonstrated
Sampling, coherent-parity-check encoding, and logical randomized benchmarking experiments used the block with postselection. Their reported benefits belong to the measured circuits and devices, not to an asymptotic threshold of this fixed code.
References: vuillot2018error, roffe2018protecting, harper2019faulttolerant
superconducting magic-state preparation circuit demonstrated
An encoded CZ resource state was prepared in this block before a code-deformation and teleportation step moved the resource into a one-logical-qubit code. The beyond-break-even result belongs to that full preparation and transfer protocol.
References: gupta2024encoding