Study on the clock-transition spectrum of cold¹⁷¹Yb ytterbium atoms

Abstract

We present a detailed study of the clock-transition spectrum of cold 171 Yb ytterbium atoms in a 1D optical lattice. A typical clock-transition spectrum with a carrier-sideband structure is observed. After minimizing the power broadening effect and compensating the stray magnetic field, the carrier linewidth is narrowed to about 16 Hz for a 60 ms interrogation time. By increasing the interrogation time to 150 ms, the linewidth is further reduced to 6.8 Hz. By applying the bias magnetic field parallel to the clock-laser polarization, a two-peak spectrum corresponding to two π transitions is obtained. Finally, spin polarization of atoms to a single desired Zeeman sublevel of the ground state is also demonstrated. The presented results will be very useful for developing better optical lattice clocks.

Modeling light shifts in optical lattice clocks

“…As a result, Yb clocks typically operate with a large population of atoms with sufficient energy to sample off-axis, peripheral lattice regions where the intensity is significantly reduced. When evaluating the lattice-induced clock frequency shifts, it is essential to separate these experiment-specific properties from the underlying physical quantities, if the results are to be tested by other clocks [18][19][20], or applied to different optical configurations.…”

Carrier thermometry of cold ytterbium atoms in an optical lattice clock

“…3 are measured in the vicinity of the magic wavelength 8 , 29 , 30 as 394,798.33(0.01) GHz. The unbroadened carrier linewidth is about 6.9 Hz, approaching the Fourier-limited linewidth with a 150 ms interrogation time 31 . The temperatures in Fig.…”

Systematic evaluation of a 171Yb optical clock by synchronous comparison between two lattice systems

“…As a detailed description of the cooling and trapping system is presented elsewhere 30 , 41 – 43 , a brief description is given here. Initially, thermal ytterbium atoms effuse from the heated oven followed by two collimators with a separation of 12 cm and diameters of 3 and 6 mm.…”

“…We have previously investigated the clock-transition spectrum in 171 Yb 30 . In this paper, we further report on the systematic evaluation of our 171 Yb optical lattice clock, which lays the groundwork for future absolute frequency measurements.…”