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arXiv · 2407.17299

Bit-flip errors in dissipative cat qubits: second-order perturbation theory

Kirill S. Dubovitskii
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Abstract

Dissipative cat qubits are known for the exponential suppression of the bit-flip rate. However, there is significant discrepancy between experimental measurements and analytical predictions of the strength of the bit-flip suppression. In this paper we resolve this discrepancy for some of the perturbations, by developing a second-order perturbation theory on top of a nonlinear dissipative Lindbladian. Following this scheme, we derive an analytical expression for the exponentially small bit-flip rate due to single-photon loss, which shows good agreement with numerical simulations. We also apply our scheme to other perturbations, such as frequency detuning and the Z gate, and find the corresponding bit-flip rates, which also show good agreement with the numerical simulation.

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Kirill S. Dubovitskii. 2024-07-24. Bit-flip errors in dissipative cat qubits: second-order perturbation theory. https://doi.org/10.1103/physreva.111.012617

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