Quantifying quantum coherence of optical cat states

The optical cat state plays an essential role in quantum computation and metrology. Here, we experimentally quantify coherence of by means relative entropy the l 1 norm a Fock basis based on prepared at rubidium D1 line. By transmitting through lossy channel, also demonstrate robustness presence loss, which is different from decoherence properties fidelity Wigner function negativity state. Our results confirm that states robust against loss pave way for application states.