Rydberg Atomic REceivers (RAREs) have shown compelling advantages in precise measurement of radio-frequency signals, empowering quantum wireless sensing. Existing RARE-based sensing systems primarily rely on the heterodyne-sensing technique, which introduces an extra reference source to serve as the atomic mixer. However, this approach entails a bulky transceiver architecture, requiring additional reference sources and transmitter-receiver signal decoupling. To address this problem, we propose a novel concept called selfheterodyne sensing. It utilizes the self-interference generated by the transmitted sensing signal as the reference signal, thus greatly simplifying the transceiver architecture. We derive the transmission model of self-heterodyne sensing and reveal that a self-heterodyne RARE functions as an atomic autocorrelator, where the received signal represents the autocorrelation of the transmitted signal at different delays. This characteristic translates the range of a sensing target into the frequency of the received signal. Inspired by this finding, a two-stage algorithm is devised to estimate the target range via frequency estimation and Newton refinement. Numerical results validate the superiority of the proposed quantum self-heterodyne sensing method.
Rydberg Atomic REceivers (RAREs) have shown compelling advantages in precise measurement of radio-frequency signals, empowering quantum wireless sensing. Existing RARE-based sensing systems primarily rely on the heterodyne-sensing technique, which introduces an extra reference source to serve as the atomic mixer. However, this approach entails a bulky transceiver architecture, requiring additional reference sources and transmitter-receiver signal decoupling. To address this problem, we propose a novel concept called selfheterodyne sensing. It utilizes the self-interference generated by the transmitted sensing signal as the reference signal, thus greatly simplifying the transceiver architecture. We derive the transmission model of self-heterodyne sensing and reveal that a self-heterodyne RARE functions as an atomic autocorrelator, where the received signal represents the autocorrelation of the transmitted signal at different delays. This characteristic translates the range of a sensing target into the frequency of the received signal. Inspired by this finding, a two-stage algorithm is devised to estimate the target range via frequency estimation and Newton refinement. Numerical results validate the superiority of the proposed quantum self-heterodyne sensing method.
Rydberg Atomic REceivers (RAREs) have demonstrated remarkable capabilities for radio-frequency signal measurement, enabling advanced quantum wireless sensing. Existing RARE-based sensing systems popularly adopt the heterodyne detection methodology, which requires an additional reference source to serve as anatomic mixer. However, this approach entails a bulky transceiver architecture and is limited in the supportable sensing bandwidth. To address these limitations, we propose a self-heterodyne sensing paradigm where the transmitter’s self-interference naturally provides the reference signal. We demonstrate that a self-heterodyne RARE functions as anatomic autocorrelator, eliminating the need for external reference sources while supporting substantially wider bandwidth than conventional heterodyne methods. Next, a two-stage algorithm is devised to perform target ranging in self-heterodyne RARE systems. This algorithm is shown to closely approach the Cramér-Rao lower bound. Furthermore, we introduce the power-trajectory (P-trajectory) design for RAREs, which maximizes the sensing sensitivity through time-varying transmission power control. An internal noise (ITN)-limitedP-trajectory is developed to capture the profile of the asymptotically optimal time-varying power in the presence of ITN only. This design is then extended to the practical P-trajectory by incorporating both the ITN and external noise. Numerical results validate that the proposed selfheterodyne sensing can achieve a ~ 100 MHz-level bandwidth with high sensitivity, substantially surpassing existing heterodyne counterparts and paving the way for high-resolution quantum wireless sensing.
Rydberg Atomic REceiver (RARE) is driving a paradigm shift in electromagnetic wave measurement by harnessing the electron transition phenomenon of Rydberg atoms. Operating at the quantum scale, such receivers have the potential to breakthrough the performance limit of classic receivers, sparking a revolution in physical-layer wireless communications. The objective of this article is to offer insights into RARE-empowered communication systems. We first provide a comprehensive introduction to the fundamental principles of RAREs. Then, a thorough comparison between RAREs and classic receivers is conducted in terms of the antenna size, sensitivity, and bandwidth. Subsequently, we overview the recent progresses in RARE-aided wireless communications, covering the frequency-division multiplexing, multiple- input-multiple-output, wireless sensing, and quantum many-body techniques. Moreover, the unique application of RARE in multi-band communication and sensing is unveiled, followed by numerical experiments to show its performance superiority over classic receivers by ~2.4 bps/ Hz in spectrum efficiency and ~7.2 dB in sensing accuracy. Finally, we conclude this article by providing promising research directions.
Quantum sensing using Rydberg atoms offers unprecedented opportunities for next-generation radar systems, transcending classical limitations in miniaturization and spectral agility. Implementing this paradigm for radar sensing, this work proposes a quantum-enhanced radar reception architecture enabled by the emerging Rydberg atomic receiver, replacing conventional antenna-to-mixer chains with a centimeter-scale vapor cell. The proposed approach is based on electromagnetically induced transparency with the Autler-Townes splitting enabling direct RF-to-optical downconversion within the atomic medium via an external co-frequency reference. To circumvent the intrinsic bottleneck on instantaneous bandwidth of atomic receiver, we invoke a non-uniform stepped-frequency synthesis strategy combining coarse laser frequency tuning with fine AC-Stark shift compensation. Additionally, we establish a nonlinear response model of the Rydberg atomic homodyne receiver and propose a customized nonlinear compensation method that extends the linear dynamic range by over 7 dB. We develop a compressive sensing algorithm (CS-Rydberg) to suppress noise and mitigate the undersampling problem. Experimentally, we demonstrate a compact prototype achieving centimeter-level ranging precision (RMSE = 1.06 cm) within 1.6-1.9 m. By synthesizing GHz-bandwidth (2.6-3.6 GHz), resolvable target separations down to 15 cm are observed under controlled sparse scenarios. These results not only validate the feasibility of quantum sensing based on Rydberg atomic receivers but also underscore the architecture's inherent scalability: by harnessing the atoms' ultra-broad spectral response, the synthesized bandwidth can be extended well beyond the current range, enabling sub-centimeter resolution in future radar systems while preserving quantum-traceable calibration and a highly simplified front end.
Quantum sensing using Rydberg atoms offers unprecedented opportunities for next-generation radar systems, transcending classical limitations in miniaturization and spectral agility. This work proposes a quantum-enhanced radar reception architecture that replaces conventional antenna-tomixer chains with a centimeter-scale vapor cell as a quantum radio frequency (RF) field sensor and mixer, enabling this paradigm for radar sensing. This approach is based on electromagnetically induced transparency, which uses Autler-Townes splitting to enable direct RF-to-optical downconversion within the atomic medium via an external co-frequency reference. To circumvent the range-resolution limitation imposed by the narrow instantaneous response of the atomic receiver, we adopt a stepped-frequency synthesis strategy involving the hybrid manipulation of Rydberg energy states. This strategy combines coarse laser frequency tuning with fine AC-Stark shift compensation. Additionally, we establish a nonlinear response model of the Rydberg atomic homodyne receiver and propose a customized nonlinear compensation method that extends the linear dynamic range by over 7 dB. We developed a compressive sensing-based algorithm (CS-Rydberg) to suppress noise and mitigate the undersampling problem. Experimentally, we demonstrate a compact prototype that achieves centimeter-level ranging precision (RMSE = 1.06 cm) within 1.6–1.9 m. By synthesizing a 1-GHz equivalent bandwidth via sparse stepped-frequency sampling over 2.6–3.6 GHz, we observe resolvable target separations down to 15 cm under controlled sparse scenarios. These results validate the feasibility of quantum sensing based on Rydberg atomic receivers and underscore the architecture’s scalability. By harnessing the atoms’ ultrabroad spectral response, the synthesized bandwidth can extend well beyond the current range. This enables sub-centimeter resolution in future radar systems while preserving quantum traceable calibration and a highly simplified front end.
As a key enabler for next-generation wireless systems, integrated sensing and communication (ISAC) requires significantly higher receiver sensitivity than conventional architectures to achieve long-range target detection, thereby introducing new challenges in receiver design. Among potential solutions, Rydberg atomic quantum receivers (RAQRs) have attracted growing attention for their unique quantum sensing capabilities. By exploiting the exceptional responsiveness of Rydberg atoms to electromagnetic fields, RAQRs enable direct and highly sensitive measurement of radio-frequency (RF) signals without relying on traditional antenna-based front ends. However, this enhanced sensitivity also renders them more vulnerable to interference, particularly from undesired targets and long-delay multipath components. To address this limitation, this article presents practical strategies for improving the interference robustness and selective reception performance of RAQRs in ISAC scenarios. Specifically, we begin with a comprehensive overview of RAQR principles and identify the interference-related challenges encountered in ISAC applications. Building on this foundation, we introduce the Actively Selective RAQR (AS-RAQR) architecture, which integrates tunable gating mechanisms to actively suppress unwanted signals. The proposed design is validated through representative case studies, followed by a discussion of open challenges and future research directions.
Harnessing multi-level electron transitions, Rydberg Atomic REceivers (RAREs) can detect wireless signals across a wide range of frequency bands, from Megahertz to Terahertz. This capability enables multi-band wireless communications and sensing (CommunSense). Existing research on multi-band RAREs primarily focuses on experimental demonstrations, lacking a tractable model to mathematically characterize their mechanisms. This issue leaves the multi-band RARE as a black box and poses challenges in its practical applications. To fill in this gap, this paper investigates the underlying mechanism of multi-band RAREs and explores their optimal performance. For the first time, an analytical transfer function with a closed-form expression for multi-band RAREs is derived by solving the quantum response of Rydberg atoms. It shows that a multi-band RARE simultaneously serves as amulti-band atomic mixerfor down-converting multi-band signals and amulti-band atomic amplifierthat reflects its sensitivity to each band. Further analysis of the atomic amplifier unveils that the intrinsic gain at each frequency band can be decoupled into aglobal gainterm and aRabi attentionterm. The former determines the overall sensitivity of a RARE to all frequency bands of wireless signals. The latter influences the allocation of the overall sensitivity to each frequency band, representing a unique attention mechanism of multi-band RAREs. The optimal design of the global gain is provided to maximize the overall sensitivity of multi-band RAREs. Subsequently, the optimal Rabi attentions are also derived to maximize the practical multi-band CommunSense performance. An experiment platform is built to validate the effectiveness of the derived transfer function, and numerical results confirm the superiority of multi-band RAREs.