Atom photoionization by the superposition of a fundamental field and its second harmonic is considered. The finite analytical expressions for the photoionization probability are obtained using the adiabatic approximation. They demonstrate that the photoelectron angular distribution has a polar symmetry when the electrical field strength has a maximal polar asymmetry and the distribution is asymmetrical when the field is symmetrical. A strict proof of the polar symmetry of the photoionization probability in the case of the electrical field with maximal asymmetry is deduced using the Keldysh-Faisal-Reiss theories. The obtained results are in agreement with the experimental data available.Atom photoionization by the superposition of a fundamental field and its second harmonic is considered. The finite analytical expressions for the photoionization probability are obtained using the adiabatic approximation. They demonstrate that the photoelectron angular distribution has a polar symmetry when the electrical field strength has a maximal polar asymmetry and the distribution is asymmetrical when the field is symmetrical. A strict proof of the polar symmetry of the photoionization probability in the case of the electrical field with maximal asymmetry is deduced using the Keldysh-Faisal-Reiss theories. The obtained results are in agreement with the experimental data available.

Physical Review AJan 1, 199519 citations

Density-matrix formalism for the photoion-electron entanglement in atomic photoionization

Thomas Radtke, S. Fritzsche, A. Surzhykov

The density-matrix theory, based on Dirac's relativistic equation, is applied for studying the entanglement between the photoelectron and residual ion in the course of the photoionization of atoms and ions. In particular, emphasis is placed on deriving the final-state density matrix of the overall system `` $\text{photoion}+\text{electron}$ ,'' including interelectronic effects and the higher multipoles of the radiation field. This final-state density matrix enables one immediately to analyze the change of entanglement as a function of the energy, angle and the polarization of the incoming light. Detailed computations have been carried out for the $5s$ photoionization of neutral strontium, leading to a photoion in a $5s\phantom{\rule{0.2em}{0ex}}^{2}S$ ${J}_{f}=1∕2$ level. It is found that the photoion-electron entanglement decreases significantly near the ionization threshold and that, in general, it depends on both the photon energy and angle. The possibility to extract photoion-electron pairs with a well-defined degree of entanglement may have far-reaching consequences for quantum information and elsewhere.The density-matrix theory, based on Dirac's relativistic equation, is applied for studying the entanglement between the photoelectron and residual ion in the course of the photoionization of atoms and ions. In particular, emphasis is placed on deriving the final-state density matrix of the overall system ``$\text{photoion}+\text{electron}$,'' including interelectronic effects and the higher multipoles of the radiation field. This final-state density matrix enables one immediately to analyze the change of entanglement as a function of the energy, angle and the polarization of the incoming light. Detailed computations have been carried out for the $5s$ photoionization of neutral strontium, leading to a photoion in a $5s\phantom{\rule{0.2em}{0ex}}^{2}S$ ${J}_{f}=1∕2$ level. It is found that the photoion-electron entanglement decreases significantly near the ionization threshold and that, in general, it depends on both the photon energy and angle. The possibility to extract photoion-electron pairs with a well-defined degree of entanglement may have far-reaching consequences for quantum information and elsewhere.

Physical Review ASep 27, 200610 citations

Photoionization of atoms

James A. R. Samson, Anthony F. Starace

Dec 1, 19790 citations

Measurement of the photoionization cross section of the 6P3/2 state of cesium

Brian M. Patterson, T. Takekoshi, R. J. Knize

We report the measurement of the absolute photoionization cross section for the ${6P}_{3/2}$ state of cesium. Cross sections were determined by measuring the photoionization rate of cesium atoms confined in a magneto-optical trap. The photoionization rate was measured by monitoring the decay of trap fluorescence during exposure to ionizing laser radiation. The measurements were made in the wavelength range 457.9 to 501.7 nm using several lines from an Ar-ion laser. Our results are compared to other experimental measurements as well as to existing theories.We report the measurement of the absolute photoionization cross section for the ${6P}_{3/2}$ state of cesium. Cross sections were determined by measuring the photoionization rate of cesium atoms confined in a magneto-optical trap. The photoionization rate was measured by monitoring the decay of trap fluorescence during exposure to ionizing laser radiation. The measurements were made in the wavelength range 457.9 to 501.7 nm using several lines from an Ar-ion laser. Our results are compared to other experimental measurements as well as to existing theories.

Physical Review AMar 1, 199934 citations

\text{photoion}+\text{electron}

,'' including interelectronic effects and the higher multipoles of the radiation field. This final-state density matrix enables one immediately to analyze the change of entanglement as a function of the energy, angle and the polarization of the incoming light. Detailed computations have been carried out for the

5s

photoionization of neutral strontium, leading to a photoion in a

5s\phantom{\rule{0.2em}{0ex}}^{2}S

{J}_{f}=1∕2

level. It is found that the photoion-electron entanglement decreases significantly near the ionization threshold and that, in general, it depends on both the photon energy and angle. The possibility to extract photoion-electron pairs with a well-defined degree of entanglement may have far-reaching consequences for quantum information and elsewhere.

We report the measurement of the absolute photoionization cross section for the

{6P}_{3/2}

state of cesium. Cross sections were determined by measuring the photoionization rate of cesium atoms confined in a magneto-optical trap. The photoionization rate was measured by monitoring the decay of trap fluorescence during exposure to ionizing laser radiation. The measurements were made in the wavelength range 457.9 to 501.7 nm using several lines from an Ar-ion laser. Our results are compared to other experimental measurements as well as to existing theories.