There is an inherent trade-off in shortwave (SW) signal reception between achieving wide operational bandwidth and high radio sensitivity. Advances in SW radio reception hold significant potential for applications in communications, broadcasting, and over-the-horizon radar. Here, we demonstrate a proof-of-concept Rydberg SW receiver integrated with the frequency-hopping technique, achieving a highly sensitive reception compatible with large bandwidth. By shifting a carrier across the whole SW band, the atomic communication maintains a stable and high data capacity far beyond the Chu–Harrington limit. The outcomes of our work facilitate the development of Rydberg atom-based RF field sensing and communication.
There is an inherent trade-off in shortwave (SW) signal reception between achieving wide operational bandwidth and high radio sensitivity. Advances in SW radio reception hold significant potential for applications in communications, broadcasting, and over-the-horizon radar. Here, we demonstrate a proof-of-concept Rydberg SW receiver integrated with the frequency-hopping technique, achieving a highly sensitive reception compatible with large bandwidth. By shifting a carrier across the whole SW band, the atomic communication maintains a stable and high data capacity far beyond the Chu–Harrington limit. The outcomes of our work facilitate the development of Rydberg atom-based RF field sensing and communication.
Rydberg atomic electric field sensors have attracted the attention of international researchers due to their powerful electric field measurement capabilities. Especially in the shortwave (SW) frequency band (3–30 MHz), using only millimeter-level sensors to receive SW signals is undoubtedly attractive. However, due to the extremely difficult excitation of the Rydberg atoms that resonate with the SW frequency, the sensitivity of the Rydberg atoms SW measurement is low. Here, we report that a method to improve the SW sensitivity by using an SW resonator, which is extremely small in electrical size ($0.0043\lambda \times 0.0035\lambda \times 0.007\lambda $), can achieve continuous resonant frequency coverage from 9.365 to 10.223 MHz and can increase the sensitivity of electric field measurement by a factor of 8633. In the state of far off-resonant, we have achieved a detectable field strength as low as$2.41~\mu $V/m with a sensitivity of$1.71~\mu V/mHz^{1/2}$using the heterodyne Rydberg atom-based mixer method, which realizes ultrahigh-sensitivity measurement of SWs. In addition, for the first time outside the laboratory, we directly received an amplitude-modulated broadcast signal with 880 km (the straight-line distance between Changsha and Baoji) at 9.81 MHz in the form of a subminiature resonator combined with a Rydberg field probe (RFP), which verified the powerful ability of this sensing scheme.
Communication technologies advance toward secure communication, with frequency hopping communication (FH-C) widely used. However, traditional FH-C is limited by slow hopping speed, narrow bandwidth, and a few hopping points. Rydberg atoms offer a solution but face challenges like poor non-resonant microwave sensitivity and local oscillator synchronization limits. Here, we propose a frequency-hopping receiver based on atomic heterodyne detection that employs high orbital angular momentum (high-OAM) Rydberg states for resonant detection of rapidly hopping radio-frequency signals across multiple, widely separated frequency bands. The high-OAM Rydberg atoms ( l =3,4,5) resonantly detect 315 MHz, 1.7 GHz, and 29.74 GHz RF hopping signals (spanning 6 octaves). With heterodyne detection and a continuous excitation scheme, the system eliminates spectral establishment time, achieving 60 khops/s without transmitter-receiver synchronization, and uses frequency combs to extend hopping points to 5 MHz around resonant frequencies. These advances demonstrate the potential of Rydberg-atom–based receivers for high-speed and wide-band frequency-hopping communication.
We present experimental results demonstrating broadband reception of a noise-like spread-spectrum waveform using a Rydberg atom-based quantum radio frequency (RF) receiver. The transmitted waveform occupies a 20 MHz bandwidth around a 2.5 GHz carrier and is intentionally engineered to exhibit noise-like spectral characteristics. To enable recovery of this broadband signal, the Rydberg sensor was configured to achieve sufficiently uniform sensitivity across intermediate frequencies up to 10 MHz (corresponding to a ±10 MHz signal band about the carrier, i.e., 20 MHz total bandwidth). Under these conditions, we demonstrate successful detection and recovery of noise-like spread-spectrum waveforms spanning a 20 MHz bandwidth. These results validate the feasibility of using atomic sensors for broadband RF waveform reception and highlight their potential in photonics-enabled RF sensing applications.
Due to the exaggerated properties of highly excited atomic states, a Rydberg-atom-based microwave receiver holds the promise to achieve superior performances in microwave metrology and communication when compared to conventional antennas. However, developing long-distance communication applications based on Rydberg atomic receiver remains challenging, because it requires the simultaneous achievement of low bit error rate (BER), high symbol rate, and weak carrier amplitude. The key to tackle this problem is to encode the information with a proper scheme that maintains high sensitivity and robustness of the Rydberg atomic receiver. Here, we use Rydberg atom-based heterodyne detection for the reception of phase-modulated microwave field, and demonstrate more than one order of magnitude improvement in reception sensitivity compared to the previously investigated amplitude-modulation scheme. Therefore, we achieve low BER communication with high symbol rate of 12 k bit/s and weak carrier amplitude of $13\phantom{\rule{0.2em}{0ex}}\text{\ensuremath{\mu}}\mathrm{V}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ simultaneously. Furthermore, we also demonstrate that our scheme is compatible with frequency-division-multiplexing communication.
The highly-excited Rydberg states are with a unique property of radio-frequency (RF) resonance, and Rydberg atoms at room temperature are promising for developing a broadband RF electric field sensor and relevant metrology standards. In this paper, the working mechanism of an atomic amplitude-modulation(AM) radio receiver is investigated in detail, and various factors affecting the communication quality are discussed. The modulation RF signal can be directly retrieved by measuring the transmission of a probe laser at resonance of rubidium D2 transition using a fast photo-diode detector, without any conventional demodulation process. Various communication experiments are tested at a 10.22 GHz carrier, and a modulation bandwidth of 1 MHz and an acceptable data transfer rate of about 1 Mbps have been achieved using current detection techniques. Owing to a potential high sensitivity and ultra-broadband capability of free-space RF field sensing, the quantum receiver has great significance compared with conventional electronics-based receivers, including but not limited to a weak signal, long-distance, and broadband communication in free space or via a fiber link.
Ultra-broadband anti-jamming communication represents a promising approach to secure and robust information transfer through spread-spectrum techniques, effectively combatting malicious interference and eavesdropping. Rydberg atoms, enhanced by waveguide coupling, facilitate ultra-broadband spectrum sensing without traditional RF components. This framework provides an experimental platform for ultra-wide anti-jamming communication. Here, we demonstrate real-time signal demodulation based on frequency-hopping spread spectrum (FHSS) in a waveguide-coupled Rydberg receiver, achieving ultra-broad frequency-hopping covering 100 kHz to 20 GHz and a hopping rate of 100 khop/s. When confined to a standard operational band (e.g., the 2.4 GHz ISM band), our system achieves a high channel density of 8 channels per MHz. Beyond this, by leveraging its ultra-broad and continuous bandwidth, the system supports over 150,000 channels. Experimental results reveal a 51 dB enhancement in narrowband interference tolerance compared with single-frequency systems, confirming its outstanding anti-jamming capability. The reported system demonstrates significant potential for secure communications based on quantum technology, especially communication in complex electromagnetic environments.