Edge graph mapping using analog information with dynamically updated weighting factors for a surface GKP code

A method, comprising:

• receiving information for a surface code, wherein the information comprises:
• a syndrome measurement history;
• and
• analog information;
• determining edges between syndrome measurements of the syndrome measurement history for respective ones of a plurality of Gottesman Kitaev Preskill (GKP) qubits of the surface code for, or across, one or more rounds of syndrome measurements,
• wherein the determined edges comprise:
• space-time correlated edges;
• and
• two-dimensional edges;
• determining weightings for the edges, wherein the analog information is used to determine the weightings, wherein GKP qubits with analog information indicating higher confidence in error correction for respective ones of the GKP qubits are weighted more heavily than other respective GKP qubits for which the analog information indicated less confidence;
• and
• decoding the surface code using the determined weightings for the edges, wherein said decoding comprises:
• extracting logical information from the syndrome measurement history for the surface code;
• and
• correcting one or more logical errors.

One or more non-transitory computer-readable media storing program instructions, that when executed on or across one or more processors, cause the one or more processors to:

• receive information for a surface code, wherein the information comprises:
• a syndrome measurement history;
• and
• analog information;
• determine edges between syndrome measurements of the syndrome measurement history for respective ones of a plurality of Gottesman Kitaev Preskill (GKP) qubits of the surface code for, or across, one or more rounds of the syndrome measurements,
• wherein the determined edges comprise:
• space-time correlated edges;
• and
• two-dimensional edges;
• determine weightings for the edges, wherein the analog information is used to determine the weightings, wherein GKP qubits with analog information indicating higher confidence in error correction for respective ones of the GKP qubits are weighted more heavily than other respective GKP qubits for which the analog information indicated less confidence;
• and
• decode the surface code using the determined weightings for the edges, wherein, to decode, the program instructions further cause the one or more processors to:
• extract logical information from the syndrome measurement history for the surface code;
• and
• correct one or more logical errors.