Magic Wavelengths for Optical-Lattice Based Cs and Rb Active Clocks

Abstract

Active clocks could provide better stabilities during initial stages of measurements over passive clocks, in which stabilities become saturated only after long-term measurements. This unique feature of an active clock has led to search for suitable candidates to construct such clocks. The other challenging task of an atomic clock is to reduce its possible systematics. A major part of the optical lattice atomic clocks based on neutral atoms are reduced by trapping atoms at the magic wavelengths of the optical lattice lasers. Keeping this in mind, we find the magic wavelengths between all possible hyperfine levels of the transitions in Rb and Cs atoms that were earlier considered to be suitable for making optical active clocks. To validate the results, we give the static dipole polarizabilities of Rb and Cs atoms using the electric dipole transition amplitudes that are used to evaluate the dynamic dipole polarizabilities and compare them with the available literature values.

The development of active optical clock

“…The optical lattice four-level AOC scheme predicts output laser power up to 24 µW with a mHz linewidth and a frequency uncertainty of 2 × 10 −15 . Singh et al obtained the magic wavelengths between all possible hyperfine levels of the transitions in Rb and Cs atoms [60], which will help build a more stable AOC. They also gave the static dipole polarizabilities of Rb and Cs atoms to validate the results.…”

“…Atomic clocks also can be divided into two categories according to their working mode, namely passive clocks and active clocks International Frequency Control Symposium (IFCS), the AOC was listed as one of the three most emerging technologies receiving the most attention in this field. Currently, there are research groups across the globe such as JILA [41][42][43], NIST, University of Colorado, Vienna University of Technology (TU Wien) [44,45], University of Copenhagen [46], University of Amsterdam [47,48], Aarhus University [49,50], Zhengzhou University [51,52], Physical Research Laboratory (India) [53], University of Hamburg [54], University of Innsbruck [55,56], Leibniz University Hannover [57], Nicolaus Copernicus University [58], Academia Sinica [59], Guru Nanak Dev University [60], Université Sorbonne Paris Nord [61], and Peking University [53,62] conducting research on bad-cavity superradiant laser based on various atomic systems. Currently, the JILA research group achieves a superradiant pulsed lasing based on the ultra-narrow transition linewidth of 87 Sr atoms with a frequency stability of 6.7 × 10 −16 at 1 s and an accuracy of 4 × 10 −15 [43].…”