An Atomic Interface for High-Dimensional Temporal Mode Quantum Networks

TL;DR

This paper presents a programmable quantum memory device that can selectively process high-dimensional temporal photon modes, enabling scalable quantum networks through coherent storage, filtering, and conversion across different bandwidths.

Contribution

The authors demonstrate a Raman quantum memory capable of dynamically shaping and interfacing high-dimensional temporal modes, a novel approach for scalable quantum information processing.

Findings

Validated selectivity across 30 orthogonal modes

Achieved high-fidelity quantum operation via process tomography

Enabled on-demand storage and conversion of temporal modes

Abstract

Temporal modes of photons are a promising encoding scheme for high-dimensional quantum networks due to their high channel capacity and fiber compatibility. However, realizing their full potential requires devices capable of synchronizing, processing and interfacing these modes across photonic and atomic bandwidths. In this work, we demonstrate a programmable high-dimensional temporal mode processor using a Raman quantum memory in warm cesium vapor. We exploit the single-mode nature of the Raman interaction kernel, dynamically shaping the control field to synthesize a tunable coherent filter that selectively addresses specific temporal waveforms. This mechanism enables on-demand storage, filtering, and conversion, providing a coherent interface between MHz- and GHz-bandwidth modes. We validate the platform's selectivity across a basis of 30 orthogonal Hermite-Gaussian modes and certify high-fidelity quantum operation via 5-dimensional process tomography. By combining deterministic mode conversion with bidirectional bandwidth interfacing, we establish the Raman memory as a critical active node for scalable quantum information processing.