Incoherent approximation for two-level system defects in quantum error correctionsimulations
ORAL
Abstract
Two-level system (TLS) defects are one of the dominant loss mechanisms in
superconducting-transmon processors. The frequencies of these defects can change over
time, leading to fluctuations in the qubit relaxation times [1]. Quantum error correction
(QEC) typically assumes constant physical error rates, and the impact TLS defects may
have on the code performance remains unexplored. However, including even a few TLS
defects in fully quantum QEC simulations significantly limits the codes and distances that
can be explored. The Random Phase Approximation (RPA) [2] can reduce the
computational overhead required to simulate TLS defects, assuming that the interactions
between the qubits and the defects are incoherent. We explore the validity of this
approximation for different TLS defect parameter regimes and under the repeated
measurement of the stabilizers of the code. Furthermore, we investigate the accuracy with
which the RPA captures the logical performance of small-distance codes in the presence
of TLS defects.
[1] P. V. Klimov et al., Phys. Rev. Lett. 121, 090502 (2018)
[2] J. Marshall et al., arXiv 2312.10277 (2023)
superconducting-transmon processors. The frequencies of these defects can change over
time, leading to fluctuations in the qubit relaxation times [1]. Quantum error correction
(QEC) typically assumes constant physical error rates, and the impact TLS defects may
have on the code performance remains unexplored. However, including even a few TLS
defects in fully quantum QEC simulations significantly limits the codes and distances that
can be explored. The Random Phase Approximation (RPA) [2] can reduce the
computational overhead required to simulate TLS defects, assuming that the interactions
between the qubits and the defects are incoherent. We explore the validity of this
approximation for different TLS defect parameter regimes and under the repeated
measurement of the stabilizers of the code. Furthermore, we investigate the accuracy with
which the RPA captures the logical performance of small-distance codes in the presence
of TLS defects.
[1] P. V. Klimov et al., Phys. Rev. Lett. 121, 090502 (2018)
[2] J. Marshall et al., arXiv 2312.10277 (2023)
*The research was sponsored by IARPA and the Army Research OXice, under the EntangledLogical Qubits program, and was accomplished under Cooperative Agreement NumberW911NF-23-2-0212. Additional support is acknowledged from NSERC, the Canada FirstResearch Excellence Fund, the Ministère de l’Économie et de l’Innovation du Québec.
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Publication: We plan on submitting an article to the arXiv prior to March Meeting. We have not yet decided where to try to publish.
Presenters
-
DVIR KAFRI
- Google LLC