Atomic superheterodyne receiver based on microwave-dressed Rydberg spectroscopy

• Published in: Nature physics Vol. 16; no. 9; pp. 911 - 915
• Main Authors: Jing, Mingyong, Hu, Ying, Ma, Jie, Zhang, Hao, Zhang, Linjie, Xiao, Liantuan, Jia, Suotang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2020; Nature Publishing Group
• Subjects: 140/125; 639/766/483; 639/766/930; Astronomy; Atomic; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; Electric fields; Electrometers; Letter; Mathematical and Computational Physics; Molecular; Noise sensitivity; Optical and Plasma Physics; Physics; Physics and Astronomy; Quantum sensors; Radio astronomy; Sensors; Superheterodyne receivers; Theoretical
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/s41567-020-0918-5

Highly sensitive phase- and frequency-resolved detection of microwave electric fields is of central importance in a wide range of fields, including cosmology 1 , 2 , meteorology 3 , communication 4 and microwave quantum technology 5 . Atom-based electrometers 6 , 7 promise traceable standards for microwave electrometry, but their best sensitivity is currently limited to a few μV cm −1  Hz −1/2 (refs. 8 , 9 ) and they only yield information about the field amplitude and polarization 10 . Here, we demonstrate a conceptually new microwave electric field sensor—the Rydberg-atom superheterodyne receiver (superhet). The sensitivity of this technique scales favourably, achieving even 55 nV cm −1  Hz −1/2 with a modest set-up. The minimum detectable field of 780 pV cm −1 is three orders of magnitude smaller than what can be reached by existing atomic electrometers. The Rydberg-atom superhet allows SI-traceable measurements, reaching uncertainty levels of 10 −8  V cm −1 when measuring a sub-μV cm −1 field, which has been inaccessible so far with atomic sensors. Our method also enables phase and frequency detection. In sensing Doppler frequencies, sub-μHz precision is reached for fields of a few hundred nV cm −1 . This work is a first step towards realizing electromagnetic-wave quantum sensors with quantum projection noise-limited sensitivity. Such a device will impact diverse areas like radio astronomy, radar technology and metrology. The Rydberg-atom superhet, based on microwave-dressed Rydberg atoms and a tailored electromagnetically induced transparency spectrum, allows SI-traceable measurements of microwave electric fields with unprecedented sensitivity.