Loss-aware optimization of realistic GKP gid states

Abstract

Realistic preparation of Gottesman-Kitaev-Preskill (GKP) states, the prime candidates for quantum computation with bosonic systems, is inevitably burdened by photon loss. We show how taking this loss into account can lead to more robust quantum states, thereby diminishing its negative influence. Using GKP squeezing as an operational figure of merit, we formulate a loss-aware optimization procedure based on the ground state representation of GKP states. Numerical simulations for square, hexagonal, and asymmetric GKP states show that the optimal preparation generally requires a different initial grid spacing than that of the desired ideal code state. For symmetric and hexagonal lattices, the optimal parameters asymptotically follow the simple scaling relation. The optimized states exhibit better GKP squeezing and greater resilience to losses. These results provide a simple and experimentally relevant strategy for improving realistic photonic GKP state preparation in the presence of known photon loss.