| Details: |
Cat and compass states exhibit interferometric patterns that are highly sensitive to small
displacements in phase space, whether these arise from coherent processes or incoherent
perturbations. These patterns include fringes on a sub-Planck scale, whose dimensions shrink
as the overall phase-space area increases. Since this area scales directly with the amplitude of
the states, we explore two non-Gaussian operations—alongside squeezing and phase-space
displacements—as means to enhance the phase-space area. These states with larger
phase-space support exhibit increased sensitivity to minute displacements, highlighting their
utility in precision metrology and quantum error correction. We further demonstrate that these
states can approach the metrological performance of single-photon probes for
continuous-variable dissipation channels and outperform Gaussian probes in dephasing
scenarios. |