Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe frequency of the ultranarrow ${^1text{S}_0} - {^3text{P}_2}$ transition in $^{87}text{Sr}$
145
0
0.0
(
0
)
Added by
Oleksiy Onishchenko
Publication date
2018
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
We determine the frequency of the ultranarrow $^{87}text{Sr}$ ${^{1}text{S}_{0}} - {^{3}text{P}_{2}}$ transition by spectroscopy of an ultracold gas. This transition is referenced to four molecular iodine lines that are observed by Doppler-free saturation spectroscopy of hot iodine vapor. The frequency differences between the Sr and the I$_2$ transitions are measured with an uncertainty of 250 kHz. The absolute frequency of the $^{87}text{Sr}$ ${^{1}text{S}_{0}} - {^{3}text{P}_{2}}$ ($text{F}=7/2$) transition is 446648775(30) MHz and limited in accuracy by the iodine reference. This work prepares the use of the Sr ${^{1}text{S}_{0}} - {^{3}text{P}_{2}}$ transition for quantum simulation and computation.
rate research
Read More
We present a gradiometer based on matter-wave interference of alkaline-earth-metal atoms, namely $^{88}$Sr. The coherent manipulation of the atomic external degrees of freedom is obtained by large-momentum-transfer Bragg diffraction, driven by laser fields detuned away from the narrow $^1$S$_0$-$^3$P$_1$ intercombination transition. We use a well-controlled artificial gradient, realized by changing the relative frequencies of the Bragg pulses during the interferometer sequence, in order to characterize the sensitivity of the gradiometer. The sensitivity reaches $1.5 times 10^{-5}$ s$^{-2}$ for an interferometer time of 20 ms, limited only by geometrical constraints. We observed extremely low sensitivity of the gradiometric phase to magnetic field gradients, approaching a value 10$^{5}$ times lower than the sensitivity of alkali-atom based gradiometers. An efficient double-launch technique employing accelerated red vertical lattices from a single magneto-optical trap cloud is also demonstrated. These results highlight strontium as an ideal candidate for precision measurements of gravity gradients, with potential application in future precision tests of fundamental physics.
Transition frequencies were determined for transitions in Ra in an atomic beam and for reference lines in Te$_2$ molecules in a vapor cell. The absolute frequencies were calibrated against a GPS stabilized Rb-clock by means of an optical frequency comb. The 7s$^2,^1$S$_0$(F = 1/2)-7s7p$,^1$P$_1$(F = 3/2) transition in $^{225}$Ra was determined to be $621,042,124(2),$MHz. The measurements provide input for designing efficient and robust laser cooling of Ra atoms in preparation of a search for a permanent electric dipole moment in Ra isotopes.
Black-body radiation (BBR) shifts of $^3!P_0-^1!S_0$ clock transition in divalent atoms Cd and Zn are evaluated using accurate relativistic many-body techniques of atomic structure. Static polarizabilities of the clock levels and relevant electric-dipole matrix elements are computed. We also present a comparative overview of the BBR shifts in optical clocks based on neutral divalent atoms trapped in optical lattices.
Laser cooling based on dark states, i.e. states decoupled from light, has proven to be effective to increase the phase-space density of cold trapped atoms. Dark-states cooling requires open atomic transitions, in contrast to the ordinary laser cooling used for example in magneto-optical traps (MOTs), which operate on closed atomic transitions. For alkali atoms, dark-states cooling is therefore commonly operated on the $D_1$ transition $n S_{1/2}rightarrow n P_{1/2}$. We show that, for $^{87}text{Rb}$, thanks to the large hyperfine structure separations the use of this transition is not strictly necessary and that $$quasi-dark state$$ cooling is efficient also on the $D_2$ line, $5 S_{1/2}rightarrow 5 P_{3/2}$. We report temperatures as low as $(4.0pm 0.3),mu$K and an increase of almost an order of magnitude in the phase space density with respect to ordinary laser sub-Doppler cooling.
A combined experimental and theoretical spectroscopic study of high-$n$, ${30 lesssim n lesssim 100}$, triplet $text{S}$ and $text{D}$ Rydberg states in $^{87}text{Sr}$ is presented. $^{87}text{Sr}$ has a large nuclear spin, ${I=9/2}$, and at high-$n$ the hyperfine interaction becomes comparable to, or even larger than, the fine structure and singlet-triplet splittings which poses a considerable challenge both for precision spectroscopy and for theory. For high-$n$ $text{S}$ states, the hyperfine shifts are evaluated non-perturbatively taking advantage of earlier spectroscopic data for the ${I=0}$ isotope $^{88}text{Sr}$, which results in good agreement with the present measurements. For the $text{D}$ states, this procedure is reversed by first extracting from the present $^{87}text{Sr}$ measurements the energies of the $^{3}text{D}_{1,2,3}$ states to be expected for isotopes without hyperfine structure ($^{88}text{Sr}$) which allows the determination of corrected quantum defects in the high-$n$ limit.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
