Construction of bias-preserving operations for pair-cat codes

Journal Article · Mon Dec 19 00:00:00 EST 2022 · Physical Review A

DOI: https://doi.org/10.1103/physreva.106.062422 · OSTI ID:2423786

Yuan, Ming  ^[1]; Xu, Qian ^[1]; Jiang, Liang  ^[1]

---

1. University of Chicago, IL (United States). Pritzker School of Molecular Engineering

Fault-tolerant quantum computation with depolarization error often requires demanding error threshold and resource overhead. If the operations can maintain high noise bias—dominated by dephasing error with small bit-flip error—we can achieve hardware-efficient fault-tolerant quantum computation with a more favorable error threshold. Distinct from two-level physical systems, multilevel systems (such as harmonic oscillators) can achieve a desirable set of bias-preserving quantum operations while using continuous engineered dissipation or Hamiltonian protection to stabilize to the encoding subspace. For example, cat codes stabilized with driven-dissipation or Kerr nonlinearity can possess a set of bias-preserving gates while continuously correcting bosonic dephasing error. However, cat codes are not compatible with continuous quantum error correction against excitation loss error, because it is challenging to continuously monitor the parity to correct photon loss errors. In this work, we generalize the bias-preserving operations to pair-cat codes, which can be regarded as a multimode generalization of cat codes, to be compatible with continuous quantum error correction against both bosonic loss and dephasing errors. In conclusion, our results open the door towards hardware-efficient robust quantum information processing with both bias-preserving operations and continuous quantum error correction simultaneously correcting bosonic loss and dephasing errors.

• Research Organization: National Quantum Information Science (QIS) Research Centers (United States). Next Generation Quantum Science and Engineering (Q-NEXT)
• Sponsoring Organization: USDOE; US Army Research Office (ARO); US Air Force Office of Scientific Research (AFOSR); National Science Foundation (NSF); David and Lucile Packard Foundation
• Grant/Contract Number: AC02-06CH11357; W911NF-18-1-0020; W911NF-18-1-0212; W911NF-16-1-0349; W911NF-21-1-0325; FA9550-19-1-0399; FA9550-21-1-0209; FA8649-21-P-0781; OMA-1936118; EEC-1941583; OMA-2137642; 2020-71479
• OSTI ID: 2423786
• Alternate ID(s): OSTI ID: 1905655
• Journal Information: Physical Review A, Vol. 106, Issue 6; ISSN 2469-9926
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English