Quantum frequency standards

Danil A. Paryohin

The problem of developing control algorithms in quantum frequency standards based on the effect of coherent population trapping is considered. The development of such algorithms will make it possible to create frequency standards with metrological characteristics that are not inferior to the characteristics of rubidium frequency standards, with reduced power consumption and overall dimensions. A method for studying the dependence of the actual value and frequency instability of quantum frequency standards based on the effect of coherent population trapping on the operating modes of individual parts of the standards is presented. As a criterion for optimizing the laser injection current, the output power of the microwave generator, and the cell temperature, we chose to minimize the effect on the shift of the actual frequency of the standard. A comparative analysis of methods for changing the radiation intensity of a surface-emitting laser with a vertical resonator has been carried out and control algorithms have been developed that take into account the features of these methods. Based on these algorithms, software and tuning methods have been developed in quantum frequency standards based on the effect of coherent population trapping. For the prototype standard, the results of measuring the frequency instability are shown. It is shown that control algorithms and tuning methods can qualitatively change the metrological characteristics of quantum frequency standards based on the effect of coherent population trapping.

Yong Hui Yu

Jacques Vanier, Cipriana Tomescu

Ding Wang, Vadim Vladimirovich Davydov

New trends in the development of navigation systems and the tasks to be solved using global navigation satellite systems, as well as the creation of the basis for deep space exploration have forced changes in the requirements for quantum frequency standards, especially in terms of frequency stability without communication sessions with the Earth. The corresponding new requirement quantum frequency standard is the quantum frequency standard on mercury-199 ions. This is now the most promising frequency standard for space systems, especially for deep space exploration. To determine the directions of modernization of the design of the quantum frequency standard on mercury-199 ions (by the new requirements), we collected and summarized information about the current research of the quantum frequency standard on mercury-199 ions in different countries of the world (USA, Russia, European Union, and China). For the first time, we performed an extended analysis comparing the characteristics of different models of quantum frequency standard on mercury-199 ions, which differ mainly in the ion traps and light sources for the excitation of mercury-202. The analysis of the technical characteristic of the quantum frequency standard on the mercury-199 ions, as well as our data on calculations of ion trap design with different electrode configurations, showed that long-term stability (105s) of the USA and Chinese models is an order of magnitude higher than that of the Russian and European Union models. The data are comparable in terms of short-term stability at the initial stage of operation. This confirmed our calculations from the parameters of the traps on the effect of electrode fabrication technologies on frequency stability. At present, this problem has not received adequate consideration in the world.

V. A. Dubkov, E. V. Kulagin, A. I. Pikhtelev +1 more

A S Grevtseva, Roman Dmitriev, Vadim Vladimirovich Davydov +1 more

Abstract The article discusses the main disadvantages of the current design of a quantum frequency standard based on rubidium-87 atoms. The main disadvantages of the current design of the quantum frequency standard on rubidium-87 atoms are considered. It is noted that the processes associated with light shifts in the optical part contribute to the greatest instability in the long-term operation of the quantum frequency standard. A solution is proposed to improve the design of the rubidium standard. A forecast for improving its metrological characteristics is presented. The results of experimental investigations are presented.