Papers by A. Taichenachev
Quantum Electronics
We demonstrate the possibility of measuring the forbidden 2 1 S 0-2 3 S 1 transition frequency (l... more We demonstrate the possibility of measuring the forbidden 2 1 S 0-2 3 S 1 transition frequency (l = 1557 nm) of a helium atom by the method of stimulated Raman scattering through the intermediate 2 3 P 1 level. Singlet (2 1 S 0) and triplet (2 3 S 1) states have long lifetimes of 20 ms and 8000 s, respectively. The transition is important for the spectroscopy of the helium atom because it relates the singlet and triplet parts of the spectrum.
We develop a nonstandard concept of atomic clocks where the blackbody radiation shift (BBRS) and ... more We develop a nonstandard concept of atomic clocks where the blackbody radiation shift (BBRS) and its temperature fluctuations can be dramatically suppressed (by one to three orders of magnitude) independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies ν 1 and ν 2) which are exposed to the same thermal environment, there exists a "synthetic" frequency ν syn ∝ (ν 1 − ε 12 ν 2) largely immune to the BBRS. As an example, it is shown that in the case of 171 Yb + it is possible to create a clock in which the BBRS can be suppressed to the fractional level of 10 −18 in a broad interval near room temperature (300±15 K). We also propose a realization of our method with the use of an optical frequency comb generator stabilized to both frequencies ν 1 and ν 2. Here the frequency ν syn is generated as one of the components of the comb spectrum and can be used as an atomic standard.
Bulletin of the Russian Academy of Sciences: Physics, 2017
The possible deep laser cooling of 24Mg atoms in a deep optical lattice in the presence of an add... more The possible deep laser cooling of 24Mg atoms in a deep optical lattice in the presence of an additional pumping field resonant to the narrow 3s3s1S0 → 3s3p3P1 (λ = 457 nm) optical transition is studied. Two quantum models of the laser cooling of atoms in the optical trap are compared. One is based on the direct numerical solution to the kinetic quantum equation for an atomic density matrix; it considers both optical pumping and quantum recoil effects during interaction between the atoms and field photons. The second, simplified model is based on decomposing the states of the atoms over the levels of vibration in the optical trap and analyzing the evolution of these states. The comparison allows derivation of optical field parameters (pumping field intensity and detuning) that ensure cooling of the atoms to minimal energies. The conditions for fast laser cooling in an optical trap are found.
2021 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS), 2021
Outside of the perturbation theory for bichromatic field of two co-propagating elliptically polar... more Outside of the perturbation theory for bichromatic field of two co-propagating elliptically polarized waves, the type of the subnatural (electromagnetically induced transparency (EIT) or absorption (EIA)) resonance is theoretically found to determined only by the angular momenta of the ground (Fg) and the excited (Fe) states of atomic gas. Herewith, the spontaneous transfer of anisotropy from the excited state to the ground one leads to the formation of the EIA resonance at the transition Fg = F → Fe = F + 1.
2018 European Frequency and Time Forum (EFTF), 2018
We study laser cooling of atoms with narrow-line optical transition, i.e. in regimes when quantum... more We study laser cooling of atoms with narrow-line optical transition, i.e. in regimes when quantum nature of laser-light interactions results significant effect on atom kinetics. We demonstrate the minimum of laser cooing temperature is reached for the light field detuning close to −3 recoil frequency, i.e. is much differ from standard Doppler cooling theory is used for semiclassical description of laser cooling. We define a set of dimensionless parameters that describe the steady state solution of cold atom distribution in laser light and cooling time. The results can be used for analysis an optimal conditions of laser cooling of atoms with narrow lines Ca, Sr and Mg are of interest for optical time standards.
New Journal of Physics, 2021
We develop a method of synthetic frequency generation to construct an atomic clock with blackbody... more We develop a method of synthetic frequency generation to construct an atomic clock with blackbody radiation (BBR) shift uncertainties below 10−19 at environmental conditions with a very low level of temperature control. The proposed method can be implemented for atoms and ions, which have two different clock transitions with frequencies ν 1 and ν 2 allowing to form a synthetic reference frequency ν syn = (ν 1 − ɛν 2)/(1 − ɛ), which is absent in the spectrum of the involved atoms or ions. Calibration coefficient ɛ can be chosen such that the temperature dependence of the BBR shift for the synthetic frequency ν syn has a local extremum at an arbitrary operating temperature T 0. This leads to a weak sensitivity of BBR shift with respect to the temperature variations near operating temperature T 0. As a specific example, the Yb+ ion is studied in detail, where the utilized optical clock transitions are of electric quadrupole (S → D) and octupole (S → F) type. In this case, temperature v...
Quantum Electronics, 2016
Vector two-wavelength interaction on reflection holographic gratings in cubic gyrotropic photoref... more Vector two-wavelength interaction on reflection holographic gratings in cubic gyrotropic photorefractive crystals A M Plesovskikh, S M Shandarov, A G Mart'yanov et al. Magneto-optical trap formed by elliptically polarised light waves for Mg atoms View the table of contents for this issue, or go to the journal homepage for more 2016 Quantum Electron. 46 661
Journal of Physics: Conference Series, 2018
The work is devoted to the study of the features and parameters of the momentum distributions of ... more The work is devoted to the study of the features and parameters of the momentum distributions of atoms laser cooled on weak optical transitions. It was shown that atoms distributions are described by a bimodal momentum distribution whose characteristics depends on the parameters of the light field. In a strong field a velocity selective coherent population trapping effect is observed.
Applied Physics Letters, 2019
Light-induced frequency shifts can be a key limiting contribution to the mid- and long-term frequ... more Light-induced frequency shifts can be a key limiting contribution to the mid- and long-term frequency instabilities in atomic clocks. In this letter, we demonstrate the experimental implementation of the combined error signal interrogation protocol to a cold-atom clock based on coherent population trapping (CPT) and Ramsey spectroscopy. The method uses a single error signal that results from the normalized combination of two error signals extracted from two Ramsey sequences of different dark periods. The single combined error signal is used to stabilize the atomic clock frequency. Compared to the standard Ramsey-CPT interrogation, this method reduces the clock frequency sensitivity to light-shift variations by more than one order of magnitude. This method can be applied in various kinds of Ramsey-based atomic clocks, sensors, and instruments.
Laser Physics Letters, 2018
We consider some implications of the mass defect on the frequency of atomic transitions. We have ... more We consider some implications of the mass defect on the frequency of atomic transitions. We have found that some well-known frequency shifts (gravitational shift and motion-induced shifts such as: quadratic Doppler and micromotion shifts) can be interpreted as consequences of the mass defect in quantum atomic physics, i.e., without the need for the concept of time dilation used in special and general relativity theories. Moreover, we show that the inclusion of the mass defect leads to previously unknown shifts for clocks based on trapped ions.
New Journal of Physics, 2018
We have developed a universal method to form the reference signal for the stabilization of arbitr... more We have developed a universal method to form the reference signal for the stabilization of arbitrary atomic clocks based on Ramsey spectroscopy. Our approach uses an interrogation scheme of the atomic system with two different Ramsey periods and a specially constructed combined error signal (CES) computed by subtracting two error signals with the appropriate calibration factor. CES spectroscopy allows for perfect elimination of probe-induced light shifts and does not suffer from the effects of relaxation, time-dependent pulse fluctuations and phase-jump modulation errors and other imperfections of the interrogation procedure. The method is simpler than recently developed auto-balanced Ramsey spectroscopy techniques [Sanner Ch et al 2018 Phys. Rev. Lett. 120 053602; Yudin V I et al 2018 Phys. Rev. Appl. 9 054034], because it uses a single error signal that feeds back on the clock frequency. The use of CES is a general technique that can be applied to many applications of precision spectroscopy.
Applied Physics Letters, 2017
A cold-atom coherent population trapping clock based on σ+−σ− interrogation realized by counter-p... more A cold-atom coherent population trapping clock based on σ+−σ− interrogation realized by counter-propagating optical fields of opposite circular polarization is presented. The simultaneous use of σ+ and σ− polarizations prevents atoms from being trapped in the end magnetic sublevels, significantly enhancing the contrast over interrogation with a single circular polarization. Because the system is based on cold atoms and there is very little relaxation, nearly complete dark states are created, and coherent population trapping resonances with maximum contrast are observed. A frequency stability of 1.3×10−11/√τ is achieved, which averages down to 2×10−13 after a 40 000 s integration period.
Physical Review Applied, 2018
When performing precision measurements, the quantity being measured is often perturbed by the mea... more When performing precision measurements, the quantity being measured is often perturbed by the measurement process itself. This includes precision frequency measurements for atomic clock applications carried out with Ramsey spectroscopy. With the aim of eliminating probe-induced perturbations, a method of generalized auto-balanced Ramsey spectroscopy (GABRS) is presented and rigorously substantiated. Here, the usual local oscillator frequency control loop is augmented with a second control loop derived from secondary Ramsey sequences interspersed with the primary sequences and with a different Ramsey period. This second loop feeds back to a secondary clock variable and ultimately compensates for the perturbation of the clock frequency caused by the measurements in the first loop. We show that such a two-loop scheme can lead to perfect compensation of measurement-induced light shifts and does not suffer from the effects of relaxation, time-dependent pulse fluctuations and phase-jump modulation errors that are typical of other hyper-Ramsey schemes. Several variants of GABRS are explored based on different secondary variables including added relative phase shifts between Ramsey pulses, external frequency-step compensation, and variable second-pulse duration. We demonstrate that a universal anti-symmetric error signal, and hence perfect compensation at finite modulation amplitude, is generated only if an additional frequency-step applied during both Ramsey pulses is used as the concomitant variable parameter. This universal technique can be applied to the fields of atomic clocks, high-resolution molecular spectroscopy, magnetically induced and two-photon probing schemes, Ramsey-type mass spectrometry, and to the field of precision measurements. Some variants of GABRS can also be applied for rf atomic clocks using CPT-based Ramsey spectroscopy of the two-photon dark resonance.
Physical Review A, 2017
Optical clock interrogation protocols, based on laser-pulse spectroscopy, are suffering from prob... more Optical clock interrogation protocols, based on laser-pulse spectroscopy, are suffering from probeinduced frequency shifts and their variations induced by laser power. Original Hyper-Ramsey probing scheme, which was proposed to alleviate those issues, does not fully eliminate the shift, especially when decoherence and relaxation by spontaneous emission or collisions are present. We propose to solve the fundamental problem of frequency shifts induced by laser probe by deriving the exact canonical form of a multi-pulse generalized Hyper-Ramsey (GHR) resonance, including decoherence and relaxation. We present a universal interrogation protocol based on composite laser-pulses spectroscopy with phase-modulation eliminating probe-induced frequency shifts at all orders in presence of various dissipative processes. Unlike frequency shifts extrapolation-based methods, a universal interrogation protocol based on ±π/4 and ±3π/4 phase-modulated resonances is proposed which does not compromise the stability of the optical clock while maintaining an ultra-robust error signal gradient in presence of substantial uncompensated ac Stark-shifts. Such a scheme can be implemented in two flavours: either by inverting clock state initialization or by pulse order reversal even without a perfect quantum state initialization. This universal interrogation protocol can be applied to atomic, molecular and nuclear frequency metrology, mass spectrometry and to the field of precision spectroscopy. It might be designed using magic-wave induced transitions, two-photon excitation and magnetically-induced spectroscopy or it might even be implemented with quantum logic gate circuit and qubit entanglement.
Quantum Electronics, 2017
Kinetics of atoms in a bichromatic field formed by elliptically polarised waves View the table of... more Kinetics of atoms in a bichromatic field formed by elliptically polarised waves View the table of contents for this issue, or go to the journal homepage for more 2017 Quantum Electron. 47 438
Physical Review A, 2015
The problem of deep laser cooling of 24 Mg atoms is theoretically studied. We propose two-stage s... more The problem of deep laser cooling of 24 Mg atoms is theoretically studied. We propose two-stage sub-Doppler cooling strategy using electro-dipole transition 3 3 P2→3 3 D3 (λ = 383.9 nm). The first stage implies exploiting magneto-optical trap with σ + and σ − light beams, while the second one uses a lin⊥lin molasses. We focus on achieving large number of ultracold atoms (T ef f <10 µK) in a cold atomic cloud. The calculations have been done out of many widely used approximations and based on quantum treatment with taking full account of recoil effect. Steady-state average kinetic energies and linear momentum distributions of cold atoms are analyzed for various light field intensities and frequency detunings. The results of conducted quantum analysis have revealed noticeable differences from results of semiclassical approach based on the Fokker-Planck equation. At certain conditions the second cooling stage can provide sufficiently lower kinetic energies of atomic cloud as well as increased fraction of ultracold atoms than the first one. We hope that the obtained results can assist overcoming current experimental problems in deep cooling of 24 Mg atoms by means of laser fields. Cold magnesium atoms, being cooled in large number down to several µK, have certain interest, for example, in quantum metrology.
Physical Review A, 2016
We develop an universal method to significantly suppress probe-induced shifts in any types of ato... more We develop an universal method to significantly suppress probe-induced shifts in any types of atomic clocks using the Ramsey spectroscopy. Our approach is based on adaptation of the synthetic frequency concept [V. I. Yudin, et al., Phys. Rev. Lett. 107, 030801 (2011)] (previously developed for BBR shift suppression) to the Ramsey spectroscopy with the use of interrogations for different dark time intervals. Universality of the method consists in arbitrariness of the possible Ramsey schemes. However, most extremal results are obtained in combination with so-called hyper-Ramsey spectroscopy [V. I. Yudin, et al., Phys. Rev. A 82, 011804(R) (2010)]. In the latter case, the probeinduced frequency shifts can be suppressed considerably below a fractional level of 10 −18 practically for any optical atomic clocks, where this shift previously was metrologically significant. The main advantage of our method in comparison with other radical hyper-Ramsey approaches [R. Hobson, et al.,
Physical Review A, 2016
Using the density matrix formalism, we prove an existence theorem of the periodic steady-state fo... more Using the density matrix formalism, we prove an existence theorem of the periodic steady-state for an arbitrary periodically-driven system. This state has the same period as the modulated external influence, and it is realized as an asymptotic solution (t→+∞) due to relaxation processes. The presented derivation simultaneously contains a simple computational algorithm non-using both Floquet and Fourier theories, i.e. our method automatically guarantees a full account of all frequency components. The description is accompanied by the examples demonstrating a simplicity and high efficiency of our method. In particular, for three-level Λ-system we calculate the lineshape and field-induced shift of the dark resonance formed by the field with periodically modulated phase. For two-level atom we obtain the analytical expressions for signal of the direct frequency comb spectroscopy with rectangular light pulses. In this case it was shown the radical dependence of the spectroscopy lineshape on pulse area. Moreover, the existence of quasi-forbidden spectroscopic zones, in which the Ramsey fringes are significantly reduced, is found. The obtained results have a wide area of applications in the laser physics and spectroscopy, and they can stimulate the search of new excitation schemes for atomic clock. Also our results can be useful for many-body physics.
Atomic and Quantum Optics: High-Precision Measurements, 1996
The motion of previously cooled atoms in a spatial grating formed by lin (perpendicular) lin lase... more The motion of previously cooled atoms in a spatial grating formed by lin (perpendicular) lin laser field configuration and the static uniform magnetic field is considered in the case of Fg equals 1 yields Fe equals 1 transition. We show that in the case of high intensity laser fields (when Rabi frequency is greater than Zeeman splitting, Doppler shift, natural width, and detuning) atoms are captured in long-lived coherent population trapping (CPT) state while heating, incoherent photon scattering, and atom-atom photon exchange are strongly reduced. The frequency, the damping time of oscillation, and the localization size are obtained for atoms moving near the bottom of potential wells in the frame of harmonic approximation. Narrowing of vibrational spectral lines due to the CPT-effect is predicted.
2015 11th Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR), 2015
We study the dynamics of the phase pulses of laser radiation with two resonant frequency componen... more We study the dynamics of the phase pulses of laser radiation with two resonant frequency components propagating in at atomic three-level medium. We show that the effect of great slowing-down occurs also for phase pulses.
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Papers by A. Taichenachev