Two-photonE1-M1optical clock

Abstract

An allowed E1-M1 excitation scheme creates optical access to the 1 S 0 → 3 P 0 clock transition in group II type atoms. This method does not require the hyperfine mixing or application of an external magnetic field of other optical clock systems. The advantages of this technique include a Doppler-free excitation scheme and increased portability with the use of vapor cells. We will discuss technical mechanisms of a monochromatic excitation scheme for a hot E1-M1 clock and briefly discuss a bichromatic scheme to eliminate light shifts. We determine the optimal experimental parameters for Hg, Yb, Ra, Sr, Ba, Ca, Mg, and Be and calculate that neutral Hg has ideal properties for a hot, portable frequency standard.

Probe light-shift elimination in generalized hyper-Ramsey quantum clocks

“…In a recent investigation of the fermionic 87 Sr optical lattice clock [5], the lattice and the probe laser light-shift corrections were characterized at the 1 × 10 −18 relative level of uncertainty. Instead probe light-shifts represent a non negligeable issue for clocks based on bosonic neutral atoms with forbidden dipole transitions activated by mixing static magnetic field with a single laser [6-9], for clocks with magic-wave induced transition in even isotopes [10], with E1-M1 two-photon laser excitations [11][12][13], for ionic systems with a single particle or highly charged systems [14,15], and molecular clocks [16]. Light-shifts are also important issues in high resolution spectroscopy and tests of theories [17].In order to reduce shifts and broadening due to inhomogeneous excitation conditions or shifts that are the result of the clock laser excitation itself, sequence of composite excitation pulses based on generalization of the Ramsey scheme [18] to more complex ones in- * E-mail address: thomas.zanon@upmc.fr cluding additional intermediate pulses with suitably selected frequency and phase steps have been introduced.…”

“…In a recent investigation of the fermionic 87 Sr optical lattice clock [5], the lattice and the probe laser light-shift corrections were characterized at the 1 × 10 −18 relative level of uncertainty. Instead probe light-shifts represent a non negligeable issue for clocks based on bosonic neutral atoms with forbidden dipole transitions activated by mixing static magnetic field with a single laser [6][7][8][9], for clocks with magic-wave induced transition in even isotopes [10], with E1-M1 two-photon laser excitations [11][12][13], for ionic systems with a single particle or highly charged systems [14,15], and molecular clocks [16]. Light-shifts are also important issues in high resolution spectroscopy and tests of theories [17].…”

Relativistically prolonged lifetime of the 2s2p3P0level of zero nuclear-spin beryllium-like ions

“…From the comparison of these two methods, which agree reasonably well for all ions along the beryllium isoelectronic sequence, the lifetime of the metastable s p P 2 2 3 0 level is found to be larger by about 2-3 orders of magnitude larger than predicted previously. This makes the 3 P 0 level of zero nuclear-spin beryllium-like ions to one of the longest living (low-lying) electronic excitations of a tightly bound system with potential applications for atomic clocks [54] or for studying correlation effects in high-Z ions [55].…”

Light propagation and atom interferometry in gravity and dilaton fields

“…Conventionally, clocks are based on recoilless internal transitions [43,67] during the initialization and readout process. However, for general pulses, the momentum of light carried by the wave vector cannot be neglected, and experiences a gravitational modification.…”