Quantum error correction with dissipatively stabilized squeezed cat qubits

TL;DR

This paper proposes a dissipatively stabilized squeezed cat qubit that significantly reduces bit-flip errors and enables faster, higher-fidelity gates, advancing noise-biased quantum error correction.

Contribution

It introduces a new stabilized squeezed cat qubit design that improves error bias and gate performance over traditional cat qubits.

Findings

Bit-flip error rate is significantly reduced with moderate squeezing.

Squeezing enables faster, higher-fidelity quantum gates.

Phase flip rate remains unchanged by squeezing.

Abstract

Noise-biased qubits are a promising route toward significantly reducing the hardware overhead associated with quantum error correction. The squeezed cat code, a non-local encoding in phase space based on squeezed coherent states, is an example of a noise-biased (bosonic) qubit with exponential error bias. Here we propose and analyze the error correction performance of a dissipatively stabilized squeezed cat qubit. We find that for moderate squeezing the bit-flip error rate gets significantly reduced in comparison with the ordinary cat qubit while leaving the phase flip rate unchanged. Additionally, we find that the squeezing enables faster and higher-fidelity gates.