Quantum optics of soliton microcombs

TL;DR

This paper investigates the quantum properties of soliton microcombs in integrated silicon carbide microresonators, revealing their potential for multimode entanglement and quantum resource applications.

Contribution

It provides the first experimental study of quantum optics in soliton microcombs, demonstrating multimode entanglement possibilities using second-order photon correlations.

Findings

Stable temporal lattice isolates multimode Gaussian state

All-to-all entanglement can be realized in the system

Pathway established for soliton-based quantum resources

Abstract

Soliton microcombs -- phase-locked microcavity frequency combs -- have become the foundation of several classical technologies in integrated photonics, including spectroscopy, LiDAR, and optical computing. Despite the predicted multimode entanglement across the comb, experimental study of the quantum optics of the soliton microcomb has been elusive. In this work, we use second-order photon correlations to study the underlying quantum processes of soliton microcombs in an integrated silicon carbide microresonator. We show that a stable temporal lattice of solitons can isolate a multimode below-threshold Gaussian state from any admixture of coherent light, and predict that all-to-all entanglement can be realized for the state. Our work opens a pathway toward a soliton-based multimode quantum resource.