You are currently viewing the summary.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
Summary
Masers, the precedent and radio-frequency (rf) counterpart of lasers, have many applications in metrology, communication, and spectroscopy. Jiang et al. (1) demonstrate a new type of maser in which rf radiation is amplified by stimulated emission from transitions between periodically modulated quantum states, called Floquet states (2), unlike a conventional maser, which uses transitions between stationary quantum states. The Floquet maser presents a phase-locked frequency comb equally spaced by the modulation frequency. With a modulating signal at a low frequency (1 to 100 mHz) converted to maser emission at high transition frequencies (∼10 Hz) of ultranarrow spectral linewidth (<0.3 mHz), the authors overcome the low-frequency noise problem in metrology and show that subpicotesla sensitivity of magnetometry is achievable. Conceivable applications of this work include precision clocks and detection of ultralight dark-matter particles such as axions.
This is an article distributed under the terms of the Science Journals Default License.