Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userDouble resonance frequency shift in a hydrogen maser
56
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We use the dressed atom formalism to calculate the frequency shift in a hydrogen maser induced by applied radiation near the Zeeman frequency, and find excellent agreement with a previous calculation made in the bare atom basis. The maser oscillates on the Delta_F = 1, Delta_m_F = 0 hyperfine transition, while the applied field is swept through the F = 1, Delta_m_F = pm 1 Zeeman resonance. We determine the effect of the applied field on the Zeeman levels using the dressed atom picture, and then calculate the maser frequency shift by coupling the dressed states to the microwave cavity. Qualitatively, the dressed-atom analysis gives a new and simpler physical interpretation of this double resonance process, which has applications in precision hydrogen Zeeman spectroscopy, e.g., in fundamental symmetry tests.
rate research
Read More
Collisions with background gas can perturb the transition frequency of trapped ions in an optical atomic clock. We develop a non-perturbative framework based on a quantum channel description of the scattering process, and use it to derive a master equation which leads to a simple analytic expression for the collisional frequency shift. As a demonstration of our method, we calculate the frequency shift of the Sr$^+$ optical atomic clock transition due to elastic collisions with helium.
Collisions between background gas particles and the trapped ion in an atomic clock can subtly shift the frequency of the clock transition. The uncertainty in the correction for this effect makes a significant contribution to the total systematic uncertainty budget of trapped-ion clocks. Using a non-perturbative analytic framework that was developed for this problem, we estimate the frequency shift in Al$^+$ ion clocks due to collisions with helium and hydrogen. Our calculations significantly improve the uncertainties in the collisional shift coefficients, and show that the collisional frequency shifts for Al$^+$ are zero to within uncertainty.
We report the theoretical evaluations of the static scalar polarizability of the 133Cs ground state and of the black body radiation shift induced on the transition frequency between the two hyperfine levels with m_F = 0. This shift is of fundamental importance in the evaluation of the accuracy of the primary frequency standards based on atomic fountains and employed in the realization of the SI second in the International Atomic Time (TAI) scale at the level of 1e-15. Our computed value for the polarizability is alpha_0=6.600(16)e-39 Cm^2/V in agreement at the level of 1e-3 with recent theoretical and experimental values. As regards the black body radiation shift we .nd for the relative hyper.ne transition frequency beta=-1.49 (7)e-14 at T = 300 K in agreement with frequency measurements reported by our group and by Bauch and Schroder [Phys. Rev. Lett. 78, 622, (1997)]. This value is lower by 2e-15 than that obtained with measurements based on the dc Stark shift and than the value commonly accepted up to now.
The measurement of the 2P^{F=2}_{3/2} to 2S^{F=1}_{1/2} transition in muonic hydrogen by Pohl et al. and subsequent analysis has led to the conclusion that the rms radius of the proton differs from the accepted (CODATA) value by approximately 4%, corresponding to a 4.9 sigma discrepancy. We investigate the finite-size effects - in particular the dependence on the shape of the proton electric form-factor - relevant to this transition using bound-state QED with nonperturbative, relativistic Dirac wave-functions for a wide range of idealised charge-distributions and a parameterization of experimental data in order to comment on the extent to which the perturbation-theory analysis which leads to the above conclusion can be confirmed. We find no statistically significant dependence of this correction on the shape of the proton form-factor.
Quantum electrodynamics in very strong Coulomb fields is one scope which has not yet been tested experimentally with suffcient accuracy to really determine whether the perturbative approach is valid. One sensitive test is the determination of the 1s Lamb Shift in highly-charged very heavy ions. The 1s Lamb Shift of hydrogen-like lead (Pb81+) and gold (Au78+) has been determined using the novel detector concept of silicon microcalorimeters for the detection of hard X-rays. The results of (260 +- 22) eV for lead and (208 +- 13) eV for gold are within error bars in good agreement with theoretical predictions. For hydrogen-like lead, this represents the most accurate determination of the 1s Lamb Shift to our knowledge.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
