Multiphoton-added cat states are constructed by repeatedly applying the creation operator to a cat state. We study in detail their photon-number distribution, $Q$ parameter, squeezing properties, and Wigner function. We show that photon addition induces a $\pi$ phase shift in the original parity configuration whenever an odd number of photons is added, reflected as swapped vanishing probabilities and phase-space displacements at the origin. Remarkably, the same process drives these states into a sub-Poissonian regime regardless of the relative phase between their coherent state components, making them valuable resources for quantum imaging, at the cost of losing quadrature squeezing, but gaining amplitude-squared one. We also discuss how these states can be generated using existing hardware.

Close

PrevNext

View figure in article

• Photon statistics
• Quantum correlations, foundations & formalism
• Quantum states of light