Rydberg Atomic Quantum Receivers for Wireless Communications: Two-Color vs. Three-Color Excitation

TL;DR

This paper proposes a three-color, five-level Rydberg atomic quantum receiver architecture for wireless communications, addressing key limitations of the traditional two-color system and demonstrating superior sensitivity and spectrum access capabilities.

Contribution

It introduces a novel 3C5L-RAQR design using all-red/infrared lasers, enabling Doppler cancellation and low-frequency detection, with an end-to-end signal model and performance evaluation.

Findings

3C5L-RAQR achieves higher sensitivity than 2C4L-RAQR.

Numerical solutions are provided using Liouvillian superoperator formalism.

3C5L-RAQR is more suitable for power-limited, broad spectrum scenarios.

Abstract

An efficient three-color (3C) laser excitation-based Rydberg atomic quantum receiver (RAQR) architecture is investigated for wireless communications, utilizing a five-level (5L) electronic transition mechanism. Specifically, the conventional two-color (2C) RAQR with the four-level (4L) excitation faces three fundamental obstacles: 1) high cost and engineering challenges due to the reliance on unstable blue lasers; 2) a fundamental sensitivity limit in thermal atoms caused by residual Doppler broadening; and 3) the inability to detect low-frequency bands due to the energy-level constraint of two-photon resonance. To address these challenges, this paper analyzes a 3C5L-RAQR architecture with all-red/infrared lasers, which not only solves the engineering cost issues but also enables effective Doppler cancellation and low-frequency detection by exhibiting the three-photon resonance. Bridging atomic physics and communication theory, an end-to-end equivalent baseband signal model is derived. Furthermore, the performance of different RAQR architectures is evaluated in terms of sensitivity, achievable capacity and spectrum access range. Moreover, we provide an exact numerical solution for practical RAQRs by employing the Liouvillian superoperator formalism. Numerical results demonstrate that the exhibited 3C5L-RAQR achieves superior sensitivity compared to the conventional 2C4L-RAQR and the classical receiver based on the conductor antenna. Finally, the inherent sensitivity-capacity trade-off is revealed, showing that the 3C5L-RAQR is more suitable for deployment in power-limited communication scenarios demanding broad spectrum access.