Quantifying quantum coherence of optical cat states

TL;DR

This paper experimentally measures the quantum coherence of optical cat states using relative entropy and l_1 norm, demonstrating their robustness against loss in quantum information applications.

Contribution

It introduces a method to quantify quantum coherence of optical cat states and shows their resilience to loss, advancing their potential use in quantum technologies.

Findings

Quantum coherence is quantifiable via relative entropy and l_1 norm.

Optical cat states maintain coherence despite transmission loss.

Coherence robustness differs from fidelity and Wigner negativity behaviors.

Abstract

Optical cat state plays an essential role in quantum computation and quantum metrology. Here, we experimentally quantify quantum coherence of an optical cat state by means of relative entropy and l_1 norm of coherence in Fock basis based on the prepared optical cat state at rubidium D1 line. By transmitting the optical cat state through a lossy channel, we also demonstrate the robustness of quantum coherence of optical cat state in the presence of loss, which is different from the decoherence properties of fidelity and Wigner function negativity of the optical cat state. Our results confirm that quantum coherence of optical cat states is robust against loss and pave the way for the application with optical cat states.