Enhancing dissipative cat qubit protection by squeezing

2025/02/11 by Rémi Rousseau, Rousseau, Rémi, Diego Ruiz +82 · 3 voices · 10 citations
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph

paper · pdf · doi:10.48550/arxiv.2502.07892

openalex publication_date 2025/02/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Dissipative cat-qubits are a promising architecture for quantum processors due to their built-in quantum error correction. By leveraging two-photon stabilization, they achieve an exponentially suppressed bit-flip error rate as the distance in phase-space between their basis states increases, incurring only a linear increase in phase-flip rate. This property substantially reduces the number of qubits required for fault-tolerant quantum computation. Here, we implement a squeezing deformation of the cat qubit basis states, further extending the bit-flip time while minimally affecting the phase-flip rate. We demonstrate a steep reduction in the bit-flip error rate with increasing mean photon number, characterized by a scaling exponent γ=4.3, rising by a factor of 74 per added photon. Specifically, we measure bit-flip times of 22 seconds for a phase-flip time of 1.3 μs in a squeezed cat qubit with an average photon number n=4.1, a 160-fold improvement in bit-flip time compared to a standard cat. Moreover, we demonstrate a two-fold reduction in Z-gate infidelity, with an estimated phase-flip probability of ε_X = 0.085 and a bit-flip probability of ε_Z = 2.65 ⋅ 10^-9 which confirms the gate bias-preserving property. This simple yet effective technique enhances cat qubit performances without requiring design modification, moving multi-cat architectures closer to fault-tolerant quantum computation.

Cited by

• Biased-noise qubits: a guide to efficient fault-tolerance using the hierarchy of errors
• Continuous Noise Model for Quantum Circuits
• Unfolded distillation: very low-cost magic state preparation for biased-noise qubits
• Elevator Codes: Concatenation for resource-efficient quantum memory under biased noise
• Ballistic bosonic noise suppression with hybrid qumode-qubit rotation gates
• Enhancing Kerr-Cat Qubit Coherence with Controlled Dissipation
• Non-linear cooling and control of a mechanical quantum harmonic oscillator
• Trotter-based quantum algorithm for solving transport equations with exponentially fewer time-steps
• Chaos and quantum regimes in n-photon driven, dissipative bosonic chains
• Scalable dissipative quantum error correction for qubit codes

Discussions

• I’m super excited to see the experimental realization of a variant of the dissipatively stabilized squeezed cat that we proposed! Congrats to Alice & Bob and everyone else involved Especially great to [bsky, 23 points, 1 comments]
• First realization of a dissipatively stabilized squeezed cat qubit (a slight variation that we called a moon cat 🌛 actually), it was super interesting to work on this with experimentalists! arxiv.org [bsky, 12 points, 1 comments]
• What if we could “squeeze” even more performance out of cat qubits? 📝 In our new paper, we show how Squeezing can drastically reduce overall errors, with a 160x increase in bit-flip lifetime while [bsky, 6 points, 0 comments]

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