A simple theoretical model describing the positive sign of subnatural-width absorption resonances in recent experiment Akulshin and co-workers [Phys. Rev. 57, 2996 (1998)] is proposed. An analytical expression for linear response to weak probe field found low-saturation limit with respect control field. It shown that subnatural resonance caused by spontaneous transfer light-induced coherence from excited level ground one.

The intrinsic magnetic fields of exoplanets affect the structure their atmospheres and plasmaspheres and, therefore, observational manifestations transit absorptions. This work proposes a new method for constraining presence or absence relatively weak fields. is based on quantum effect atomic alignment lower energy level resulting in changing absorption probabilities individual transitions multiplets from equilibrium 2J+1 value. It appears to be sensitive above ~0.001 G. We applied this some...

The amplitude of Λ resonance in alkali atoms is limited by perturbing cycling transitions the case D2 line or existence additional trapping states D1 line. We propose to eliminate these extra using two counter-propagating bichromatic fields orthogonal circular polarizations. experiment accordance with theoretical proposal. result refers small-size cells and important for applications miniaturized atomic clocks.

The saturated absorption technique is an elegant method widely used in atomic and molecular physics for high-resolution spectroscopy, laser frequency standards metrology purposes. We have recently discovered that a scheme with dual-frequency can lead to significant sign reversal of the usual Doppler-free dip, yielding deep enhanced-absorption spike. In this paper, we report detailed experimental investigations phenomenon, together full in-depth theoretical description. It shown several...

Light-induced frequency shifts can be a key limiting contribution to the mid and long-term instability in atomic clocks. In this letter, we demonstrate experimental implementation of combined error signal interrogation protocol cold-atom clock based on coherent population trapping (CPT) Ramsey spectroscopy. The method uses single that results from normalized combination two signals extracted sequences different dark periods. is used stabilize frequency. Compared standard Ramsey-CPT...

Light shifts are known to be an important limitation the mid- and long-term fractional frequency stability of different types atomic clocks. In this article, we demonstrate experimental implementation anti-light-shift interrogation protocol onto a continuous-wave (cw) microcell clock based on coherent population trapping (CPT). The method, inspired by autobalanced Ramsey spectroscopy technique demonstrated in pulsed clocks, consists extraction information from two successive light-shifted...

The method for observing the high-contrast and narrow-width resonances of electromagnetically induced absorption (EIA) in Hanle configuration under counterpropagating light waves is proposed. We theoretically analyze a probe wave presence one with same frequency as function static magnetic field applied along vectors waves, propagating vapour cell. Here, an example, we study "dark" type atomic dipole transition Fg=1-->Fe=1 D1 line 87Rb, where usually transparency (EIT) can be observed. To...

We develop a universal method to significantly suppress probe-induced shifts in any type of atomic clock using Ramsey spectroscopy. Our approach is based on the adaptation synthetic frequency concept [V. I. Yudin et al., Phys. Rev. Lett. 107, 030801 (2011)] (previously developed for blackbody radiation shift suppression) spectroscopy with use interrogations different dark time intervals. The most significant suppression obtained combination so-called hyper-Ramsey technique A 82, 011804(R)...

We report on a comparative analysis of quenched sideband cooling in trapped ions. introduce theoretical approach for time-efficient simulation the temporal characteristics and derive optimal conditions providing fast laser into ion's motional ground state. The simulations were experimentally benchmarked with single $^{172}$Yb$^+$ ion confined linear Paul trap. Sideband was carried out narrow quadrupole transition, enhanced an additional clear-out controlling effective linewidth transition....

We present a complete set of analytical and invariant expressions for the steady-state density matrix atoms in resonant radiation field with arbitrary intensity polarization. The drives closed dipole transition values angular momenta $J_{g}$ $J_{e}$ ground excited state. is expressed terms spherical harmonics complex direction given by polarization vector. generalization to case broad-band given. indicate various applications these results.

Using a 1 --> 2 transition as an analytically tractable model, we discuss in detail magneto-optical resonances of both electromagnetically induced absorption (EIA) and transparency (EIT) types the Hanle configuration. The analysis is made for arbitrary rate depolarizing collisions excited state elliptical field polarization. obtained results clearly show that main reason EIA subnatural resonance spontaneous transfer anisotropy from level to ground level. In case predict negative structures...

Optical clock interrogation protocols, based on laser-pulse spectroscopy, suffer from probe-induced frequency shifts and their variations induced by laser power. The original hyper-Ramsey probing scheme, which was proposed to alleviate those issues, does not fully eliminate the shift, especially when decoherence relaxation spontaneous emission or collisions are present. We propose solve fundamental problem of probe deriving exact canonical form a multipulse generalized resonance, including...

We identify the specific polarizations for two components of a bichromatic field, which produce pure superposition states atoms with magnetic quantum number $m$ via coherent population trapping. The are composed Zeeman substates ground-state hyperfine levels arbitrary angular momenta ${F}_{1}$ and ${F}_{2}$. It is established that in general case $m\ensuremath{\ne}0$, optical fields elliptical needed preparation such state. shown analitically unique advantage $D1$ line (over $D2$ line)...

We propose a simple and effective way of creating pure dark superposition states. The generation states is carried out by using bichromatic radiation with controllable polarization ellipticity. derived analytic formulas for elipticity to obtain different Zeeman sublevels alkali atoms. Experimentally we accumulated ~60% the atoms in 0-0 state D1 line Rb87

We consider a magneto-optical trap (MOT) formed by elliptically polarised waves for 24Mg atoms on closed optical 3P2 → 3D3 (λ = 383.8 nm) transition in the e – θ configuration of field. Compared with known MOT circularly (σ+ σ- configuration), suggested fields allows deeper sub-Doppler cooling trapped atoms, which cannot be implemented conventional σ+ configuration.

Generally, conditions for deep sub-Doppler laser cooling do not match strong atomic localization, that takes place in a deeper optical potential and leads to higher temperature. Moreover, given detuning the secular approximation, which is frequently used quantum description of cooling, fails. Here we investigate localization potential, using full approach density matrix beyond approximation. It shown created by light field with polarization gradients, can be as an alternative method...

We present the theoretical analysis of sub-Doppler laser cooling 24Mg atoms using dipole transition 33P2→33D3 under two counterpropagating light waves with opposite circular polarizations (one-dimensional σ+σ– configuration). For numerical calculations standard semi-classical approach based on Fokker–Planck equation for linear momentum distribution is exploited. The distributions are gained beyond limits slow approximation and an arbitrary field intensity. absence these allows us to...

We propose and demonstrate a simple technique for identifying the central Ramsey fringe of pulsed coherent population trapping resonance. An auxiliary optical field is applied during free evolution time. It suppresses nearby fringes but does not change amplitude practically, which marks it out clearly. The theory based on density matrix equations Λ-system configuration levels interrogation that takes into account presented compared to experiment with 87Rb atoms. also improving middle-...