Integrated spectrally multiplexed light-matter interface at telecom band

TL;DR

This paper demonstrates an integrated telecom-band light-matter interface with five spectral channels on a chip, capable of storing and recalling entangled photons with high fidelity, advancing scalable quantum networks.

Contribution

It introduces a broadband, multiplexed on-chip quantum memory at telecom wavelengths with five spectral channels, enabling high-rate quantum communication.

Findings

Achieved 4 GHz bandwidth per channel with 15 GHz spacing.

Stored and recalled time-bin entangled photons with >92% fidelity.

Demonstrated a 152 ns storage time on an integrated chip.

Abstract

Light-matter interface is an important building block for long-distance quantum networks. Towards a scalable quantum network with high-rate quantum information processing, it requires to develop integrated light-matter interfaces with broadband and multiplexing capacities. Here we demonstrate a light-matter interface at telecom band in an integrated system. A five-spectral-channel atomic-frequency-comb photonic memory is prepared on a laser-written Er3+:LiNbO3 chip. The bandwidth of each channel is 4 GHz with a channel spacing of 15 GHz. The signal photons from time-bin entangled photon pairs at telecom band are sent into the on-chip memory and recalled after a storage time of 152 ns. The entanglement-preserving nature of our integrated quantum interface is assessed by an input/output fidelity of >92% for all the five spectral channels. Our light-matter interfaces constitute a notable step forward toward a high-rate quantum network involving integrated device.