Deterministic preparation of optical squeezed cat and Gottesman-Kitaev-Preskill states

Large-amplitude squeezed cat and high-quality Gottesman-Kitaev-Preskill (GKP) states are powerful resources for quantum error correction. However, previous schemes in optics are limited to low success probabilities, small amplitudes, and low squeezing. We overcome these limitations and present scalable schemes in optics for the deterministic preparation of large-amplitude squeezed cat states using only Gaussian operations and photon-number measurements. These states can be bred to prepare high-quality approximate GKP states, showing that GKP error correction in optics is technically feasible in near-term experiments.