Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Experimental and Theoretical Physics

Localization and kinetics of an atom in the spectral filtration of its resonance fluorescence

L. V. Il’ichev

Published Feb 1, 2008• 0 citations
Publisher

Abstract

It is shown that spectral filtration of a significant fraction of radiation of a resonantly fluorescing atom changes its kinetics. The effect of a spectral observation event on the behavior of an atom is demonstrated by two examples: localization of an atom at its flight through a region occupied by a standing light wave and translatory dynamics of an atom at its motion along a standing light wave. In the first case, localization probabilities are calculated in the absence of spontaneous emission events and for one photoemission event. The arising distribution over the atomic momentum, which is sensitive to spectral filtration, is also calculated for one photoemission event. In the second example, it is shown that spectral filtration of spontaneous emission leads to the occurrence of an anomalous additive to the force acting on an atom in the standing-wave field.

DOI
10.1134/s1063776108020040

Related papers

SPECTROSCOPIC TECHNIQUES FOR SINGLE ATOM LOCALIZATION

Sajid, Qamar

Entanglement of the atom and field leads towards the measurement of the state of the atom or field depending on the kind of measurement made. Taking advantage of this fact, we propose spectroscopic methods for the single atom localization within the subwavelength domain of the optical standing wave field. \n \nWhen a two-level atom interacts with some intense radiation field the spectrum of the scattered light signal exhibits a three-peak Mollow spectrum. We propose a scheme of atom localization based on the resonance fluorescence from a two-level atom interacting with a standing wave field. The Rabi frequency is considered to be position dependent and therefore, the spontaneously emitted photon carries the information about the center-of-mass motion of the atom. This leads to the localization of the single atom by measuring the frequency of the spontaneously emitted photon even during the passage of the atom through the standing wave field. We predict a spatial resolution in position information of up to λ/60 where λ is the optical wavelength. \n \nDetuning of the coherent field with the atomic transition plays an important role in the characterization of the peaks present in the Autler- Townes spectrum of a three-level atom. Strong line narrowing is observed in one of the peaks of the Autler- Townes doublet depending on the choice of the detuning. We investigate how this detuning effects the position information of the atom inside the standing wave field in upper-level and lower-level coupling schemes of Autler- Townes microscopy. We show an enhancement in precision position measurement by factor of at least 4 in upper-level coupling scheme due to the quantum interference phenomenon. This enhancement is not observed in lower-level coupling scheme where the quantum interference is not taking place. \n \nWe also consider a system where a three-level atom is interacting with a monochromatic radiation field in such a way that the decay takes place from upper level to the intermediate level with a rate T and from intermediate level to lower level at a rate γ. This type of system exhibits a non stationary scattered light signal. We report the results of the spontaneous emission spectrum for non stationary scattered light signal by using the definition of time-dependent physical spectrum. This is a rare example of problems where time-dependent physical spectrum can be calculated exactly. We study the characteristics of the spontaneous spectrum for a resonant and off-resonant case and show that this physical spectrum recovers the results of earlier work quite successfully. We also show that the decay rate r disturbs the atomic coherence and finally eliminates the dark line from the center of the spontaneous spectrum. Here we only consider upper-level coupling case for the time-dependent spontaneous spectrum because in lower-level coupling case the system automatically evolved a pumping mechanism due to the coupling of ground level to the upper level via radiation field. Thus a steady-state limit exists in lower-level coupling scheme. \n \nWe investigate the phenomenon of atom localization by using the non stationary Autler-Townes microscopy. The decay rate T reduces the precision in position measurement which is consistent with the results of the non stationary spontaneous emission spectrum. This is due to the fact that for the upper-level coupling case, the standing wave field is coupled to atomic transition and it induces a coherence in the upper-level atomic transition but the spontaneous decay from the upper level to the intermediate level disturbs this coherence. When the effect of the spontaneous decay dominates the coherence effect the quantum interference phenomenon vanishes and thus the precision in localization reduces.

•Jan 1, 2000•0 citations

Atomic motion in resonant fluctuating laser radiation

R. J. Cook

The effect of field fluctuations on the motion of a two-level atom in resonant laser radiation is investigated theoretically. The internal motion of the atom is treated quantum mechanically (optical Bloch equations); the translational motion, which is coupled to the internal motion, is treated classically (Ehrenfest's theorem); and the fluctuating radiation is treated as a classical electromagnetic wave with stochastic phase (phase-diffusion model). An expression for the radiation force and equations of motion for the ensemble-averaged Bloch vector are derived and used to calculate (i) the radiation force in a plane running wave, (ii) the steady-state radiation force in a general standing wave, and (iii) the dissipative force in a plane standing wave in the limit of strong phase fluctuations. In case (iii) it is found that the atomic velocity is damped when the radiation is tuned above resonance, which is opposite to the case of a weak coherent standing wave, in which damping occurs for radiation tuned below resonance. It is shown that fluctuations have a substantial effect on the radiation force only when the spectral width of the radiation approaches or exceeds the spontaneous emission rate.

Physical Review A•Jan 1, 1980•26 citations

Channeling and velocity bunching of atoms in a standing wave laser field

Yuzhu Wang, W. Q. Cai, Y. D. Cheng +2 more

The kinetic behavior of atomic motion in a standing wave laser field has been extensively studied because it is important to trapping, cooling, and manipulating atoms. The radiative force acting on atoms in the standing wave is related to the processes of induced transitions and spontaneous emission. The probabilities of these processes depend on the detuning between laser and atomic frequencies, the intensity and structure of the field, as well as the velocity of the atom.1-3

Quantum Electronics and Laser Science Conference•Apr 24, 1989•0 citations

Motion of an atom due to anisotropic filtering of its resonance fluorescence

L. V. Il’ichev

The effect of the specific anisotropy of the environment on the dynamics of a resonantly fluorescing atom is analyzed in a one-dimensional model. The environmental anisotropy, which is manifested as different spectral selectivities of the absorption of spontaneous photons emitted by the atom in different directions, results in the anisotropy of the photon emission rate giving rise to a nonzero recoil force on the atom. The effect under optimal conditions can reach one-quarter of the recoil momentum per single photon emission. This force is directed toward the weaker spectral selectivity.

Journal of Experimental and Theoretical Physics Letters•Jan 1, 2009•0 citations

Atom localization via resonance fluorescence

Sajid Qamar, Shi-Yao Zhu, Muhammad Suhail Zubairy

We propose a simple scheme of atom localization based on resonance fluorescence from a standing-wave field. The Rabi frequency is position dependent and therefore the spontaneously emitted photon carries the information of the atomic center-of-mass motion. This leads to atom localization even during the flight through the standing-wave field.

Physical Review A•May 11, 2000•197 citations

Dynamical localization of atomic de Broglie waves: The influence of spontaneous emission

R. Graham, Syuji Miyazaki

The quantized center-of-mass dynamics of two-level atoms in a periodically modulated standing-wave laser field is analyzed, including the decohering effect of spontaneous emission. Under conditions appropriate for the occurrence of dynamical localization as determined in previous work, we predict a random diffusive motion of dynamically localized de Broglie waves due to spontaneous emission and calculate the diffusion constant and the diffusing distribution of wave packets. \textcopyright{} 1996 The American Physical Society.

Physical Review A•Apr 1, 1996•32 citations
It is shown that spectral filtration of a significant fraction of radiation of a resonantly fluorescing atom changes its kinetics. The effect of a spectral observation event on the behavior of an atom is demonstrated by two examples: localization of an atom at its flight through a region occupied by a standing light wave and translatory dynamics of an atom at its motion along a standing light wave. In the first case, localization probabilities are calculated in the absence of spontaneous emission events and for one photoemission event. The arising distribution over the atomic momentum, which is sensitive to spectral filtration, is also calculated for one photoemission event. In the second example, it is shown that spectral filtration of spontaneous emission leads to the occurrence of an anomalous additive to the force acting on an atom in the standing-wave field.
Entanglement of the atom and field leads towards the measurement of the state of the atom or field depending on the kind of measurement made. Taking advantage of this fact, we propose spectroscopic methods for the single atom localization within the subwavelength domain of the optical standing wave field. \n \nWhen a two-level atom interacts with some intense radiation field the spectrum of the scattered light signal exhibits a three-peak Mollow spectrum. We propose a scheme of atom localization based on the resonance fluorescence from a two-level atom interacting with a standing wave field. The Rabi frequency is considered to be position dependent and therefore, the spontaneously emitted photon carries the information about the center-of-mass motion of the atom. This leads to the localization of the single atom by measuring the frequency of the spontaneously emitted photon even during the passage of the atom through the standing wave field. We predict a spatial resolution in position information of up to λ/60 where λ is the optical wavelength. \n \nDetuning of the coherent field with the atomic transition plays an important role in the characterization of the peaks present in the Autler- Townes spectrum of a three-level atom. Strong line narrowing is observed in one of the peaks of the Autler- Townes doublet depending on the choice of the detuning. We investigate how this detuning effects the position information of the atom inside the standing wave field in upper-level and lower-level coupling schemes of Autler- Townes microscopy. We show an enhancement in precision position measurement by factor of at least 4 in upper-level coupling scheme due to the quantum interference phenomenon. This enhancement is not observed in lower-level coupling scheme where the quantum interference is not taking place. \n \nWe also consider a system where a three-level atom is interacting with a monochromatic radiation field in such a way that the decay takes place from upper level to the intermediate level with a rate T and from intermediate level to lower level at a rate γ. This type of system exhibits a non stationary scattered light signal. We report the results of the spontaneous emission spectrum for non stationary scattered light signal by using the definition of time-dependent physical spectrum. This is a rare example of problems where time-dependent physical spectrum can be calculated exactly. We study the characteristics of the spontaneous spectrum for a resonant and off-resonant case and show that this physical spectrum recovers the results of earlier work quite successfully. We also show that the decay rate r disturbs the atomic coherence and finally eliminates the dark line from the center of the spontaneous spectrum. Here we only consider upper-level coupling case for the time-dependent spontaneous spectrum because in lower-level coupling case the system automatically evolved a pumping mechanism due to the coupling of ground level to the upper level via radiation field. Thus a steady-state limit exists in lower-level coupling scheme. \n \nWe investigate the phenomenon of atom localization by using the non stationary Autler-Townes microscopy. The decay rate T reduces the precision in position measurement which is consistent with the results of the non stationary spontaneous emission spectrum. This is due to the fact that for the upper-level coupling case, the standing wave field is coupled to atomic transition and it induces a coherence in the upper-level atomic transition but the spontaneous decay from the upper level to the intermediate level disturbs this coherence. When the effect of the spontaneous decay dominates the coherence effect the quantum interference phenomenon vanishes and thus the precision in localization reduces.
The effect of field fluctuations on the motion of a two-level atom in resonant laser radiation is investigated theoretically. The internal motion of the atom is treated quantum mechanically (optical Bloch equations); the translational motion, which is coupled to the internal motion, is treated classically (Ehrenfest's theorem); and the fluctuating radiation is treated as a classical electromagnetic wave with stochastic phase (phase-diffusion model). An expression for the radiation force and equations of motion for the ensemble-averaged Bloch vector are derived and used to calculate (i) the radiation force in a plane running wave, (ii) the steady-state radiation force in a general standing wave, and (iii) the dissipative force in a plane standing wave in the limit of strong phase fluctuations. In case (iii) it is found that the atomic velocity is damped when the radiation is tuned above resonance, which is opposite to the case of a weak coherent standing wave, in which damping occurs for radiation tuned below resonance. It is shown that fluctuations have a substantial effect on the radiation force only when the spectral width of the radiation approaches or exceeds the spontaneous emission rate.
The effect of the specific anisotropy of the environment on the dynamics of a resonantly fluorescing atom is analyzed in a one-dimensional model. The environmental anisotropy, which is manifested as different spectral selectivities of the absorption of spontaneous photons emitted by the atom in different directions, results in the anisotropy of the photon emission rate giving rise to a nonzero recoil force on the atom. The effect under optimal conditions can reach one-quarter of the recoil momentum per single photon emission. This force is directed toward the weaker spectral selectivity.
The quantized center-of-mass dynamics of two-level atoms in a periodically modulated standing-wave laser field is analyzed, including the decohering effect of spontaneous emission. Under conditions appropriate for the occurrence of dynamical localization as determined in previous work, we predict a random diffusive motion of dynamically localized de Broglie waves due to spontaneous emission and calculate the diffusion constant and the diffusing distribution of wave packets. \textcopyright{} 1996 The American Physical Society.