Experimental measurement of the doubled gravitational frequency shift in a quantum level on hydrogen clocks

V.F. Fateev, Y.F. Smirnov, S.S. Donchenko, F.R. Smirnov, E.A. Rybakov

FSUE “VNIIFTRI”, Mendeleevo, Moscow region, Russia

Al’manac of Modern Metrology № 1 (29) 2022, pages 115–126

Abstract. For the first time, the doubled effect of the gravitational frequency shift in the gravitational field of the Earth was measured using stationary and transportable hydrogen quantum clocks separated by 34 m in height. The clocks were connected by a radio channel at a frequency of about 10 MHz, implemented by modulating an optical carrier in an optical fiber. The measure­ments are based on the simultaneous use and addition of two effects: the effect of changing the frequency of the master oscillator of the transported quantum clock, which occurs due to time dilation in the gravitational field, as well as the classical effect of gravitational frequency shift in the radio channel. The effects are the same in magnitude, have opposite signs, and therefore, when moving the mobile watch in height, they are summed up.

Keywords: quantum level, gravitational frequency shift, hydrogen frequency standard.

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