US 12,261,627 B2
Decoding errors using quantum subspace expansion
Jarrod Ryan McClean, Marina Del Rey, CA (US); Ryan Babbush, Venice, CA (US); and Zhang Jiang, El Segundo, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Filed by Google LLC, Mountain View, CA (US)
Filed on Sep. 22, 2023, as Appl. No. 18/473,029.
Application 18/473,029 is a division of application No. 17/433,459, granted, now 11,894,860, previously published as PCT/US2020/021236, filed on Mar. 5, 2020.
Claims priority of provisional application 62/814,155, filed on Mar. 5, 2019.
Prior Publication US 2025/0030440 A1, Jan. 23, 2025
Int. Cl. H03M 13/00 (2006.01); G06N 10/00 (2022.01); H03M 13/15 (2006.01)
CPC H03M 13/1575 (2013.01) [G06N 10/00 (2019.01)] 9 Claims
OG exemplary drawing
 
1. A method for correcting a result of a quantum computation, the method comprising:
selecting a quantum error correcting code to perform the quantum computation, wherein the quantum error correcting code is defined by a respective set of stabilizer generators;
selecting a linear combination of stabilizer operators generated by the stabilizer generators;
determining values of coefficients of the stabilizer operators in the linear combination, comprising solving a generalized eigenvalue problem for a corresponding quantum error correcting code Hamiltonian;
measuring an expansion correction of a physical observable over an output quantum state of the quantum computation using the stabilizer operators in the linear combination of stabilizer operators, wherein the physical observable corresponds to the result of the quantum computation; and
determining a corrected result of the quantum computation using the measured expansion correction of the physical observable and the determined values of the coefficients of the stabilizer operators in the linear combination.