Physicists from Novosibirsk made the discovery together with colleagues from the USA and France.
The researchers’ article was published in the journal Physical Review Applied.
“Atomic clocks are by far the most accurate time measuring instruments. If the clock was started at the moment of the formation of the Universe, then by today it would have deviated by a fraction of a second, ” one of the authors of the project, chief researcher of the ILP SB RAS, Doctor of Physical and Mathematical Sciences, Valery Yudin, told the Science in Siberia portal.
Such devices are now used in space stations, for navigation in GLONASS and GPS systems and in some other areas. Therefore, their accuracy and stability are important. In the operation of atomic clocks, despite their great accuracy, deviations can occur that affect the measurement results. For example, today satellite navigation systems can calculate coordinates with an accuracy of several meters. Improvements in atomic clock technology will reduce this value to a few centimeters.
At the moment, atomic clocks have an instability from 10-16 to 10-18. In many cases, this instability is due to field shear. This shift is due to the action of the electromagnetic field, which generates a local oscillator in the watch itself. In addition to its main job of creating the desired frequencies in the device, this element generates electromagnetic pulses that shift the vibration frequency in the atoms. Therefore, in order to increase the stability and accuracy of atomic clocks, scientists are trying to create methods to reduce this shift.
Often in atomic clocks, physicists use a laser to create the required vibration frequency. Such a laser can influence the behavior of the field shift. Russian researchers have found a way to reduce the field shift in an atomic clock using anti-shift. These influences are the same in strength, but different in sign, therefore, they compensate each other, thereby reducing the instability of the device.
In their work, the scientists used the principle of two feedback loops. The loop is a ring system of causally related elements that influence each other. On the first loop, the laser frequency is stabilized, and on the second loop, “natural” and artificial shifts are compensated. To create an anti-shift, scientists programmed the laser so that it “fired” at the atomic clock with an additional negative frequency shift.
The new method turned out to be quite simple and easily corrected. Now physicists plan to investigate the application of the new method and understand how best to implement it in practice.