Noise of a single-ion frequency standard

Autor: B. Appasamy, Philippe Courteille, Yves Stalgies, Ralf Huesmann, Peter E. Toschek
Rok vydání: 1996
Předmět:
Zdroj: Annales Des Télécommunications. 51:373-382
ISSN: 1958-9395
0003-4347
DOI: 10.1007/bf02996025
Popis: A frequency source supposed to serve as a standard requires feedback for short-term and long-term frequency control. A spectral discriminant for short-term control may be provided, in the microwave regime, by a hyperfine resonance of a multi-ion ensemble confined in an electrodynamic trap, and in the optical regime by an eigenmode of a focal Fabry-Perot cavity. For long-term frequency control, resonances of single trapped ions are discriminants of superior accuracy although the controlled frequency shows random fluctuations caused by noise on the feedback signal. Its fundamental contribution is quantum projection noise. The detection of fluorescence for the generation of feedback is incompatible with the ions being prepared in a superposition state in the excitation by the wave emitted from the oscillator. Attempts of circumventing this limitation by preparing ensembles of correlated ions prior to the measurement (spin squeezing) are reviewed.
Databáze: OpenAIRE