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 Physics Conference Series

Time delay in atomic photoionization with circularly polarized light

Anatoli S. Kheifets, Igor A. Ivanov

Published Apr 10, 2014• 3 citations
Publisher

Abstract

We present a study of the time delay in atomic photo-ionization by circularly polarized laser pulse. We considered initial electron states that are co- and counter-rotating with respect to the electric field. We found, that similarly to the photoelectron spectra, studied extensively in the literature, the time delays are markedly different for these two orientations, depending sensitively on the field strengths and pulse durations.

DOI
10.1088/1742-6596/488/3/032003

Related papers

Time delay in atomic photoionization with circularly polarized light

Igor A. Ivanov, Anatoli S. Kheifets

We study time delay in atomic photoionization by circularly polarized light. By considering the Li atom in an excited $2p$ state, we demonstrate a strong time-delay asymmetry between the photoemission of the target electrons that are co- and counter-rotating with the electromagnetic field in the polarization plane. In addition, we observe the time-delay sensitivity to the polar angle of the photoelectron emission in the polarization plane. This modulation depends on the shape and duration of the electromagnetic pulse.

Physical Review A•Mar 7, 2013•48 citations

Circular dichroism in atomic resonance-enhanced few-photon ionization

A. H. N. C. De Silva, T. Moon, K. L. Romans +8 more

We investigate few-photon ionization of lithium atoms prepared in the polarized $2p\phantom{\rule{0.16em}{0ex}}({m}_{\ensuremath{\ell}}=+1)$ state when subjected to femtosecond light pulses with left- or right-handed circular polarization at wavelengths between 665 and 920 nm. We consider whether ionization proceeds more favorably for the electric field co- or counter-rotating with the initial electronic current density. Strong asymmetries are found and quantitatively analyzed in terms of ``circular dichroism'' (CD). While the intensity dependence of the measured CD values is rather weak throughout the investigated regime, a very strong sensitivity on the center wavelength of the incoming radiation is observed. While the co-rotating situation overall prevails, the counter-rotating geometry is strongly favored around 800 nm due to the $2p\text{\ensuremath{-}}3s$ resonant transition, which can only be driven by counter-rotating fields. The observed features provide insights into the helicity dependence of light-atom interactions, and on the possible control of electron emission in atomic few-photon ionization by polarization-selective resonance enhancement.

arXiv:2103.07499•Physical Review A•May 28, 2021•24 citations

Relativistic effects in time delay of atomic photoionization

Igor A. Ivanov, Anatoli S. Kheifets

We study relativistic effects in the time delay of atomic photoionization using an example of the Xe atom subjected to a circularly polarized electromagnetic pulse. We find that while relativistic effects play only a fairly small role for both the ionization probabilities and the time delay of the corotating electron with the same sign of the angular momentum projection as the circularly polarized light, these effects produce substantial change in the time delay for a counter-rotating electron with the opposite sign of the angular momentum projection.

Physical Review A•Apr 7, 2014•10 citations

Measurement of ionization delays in atomic resonance-enhanced multiphoton ionization using photoelectron vortices

D. Köhnke, Tim Bayer, M. Wollenhaupt

We study time delays in atomic multiphoton ionization (MPI) using the phase-sensitive detection of photoelectron vortices. Photoelectron vortices are created by MPI with counterrotating circularly polarized (CRCP) ultrashort double-pulse sequences. The vortices are characterized by a spiral-shaped photoelectron momentum distribution (PMD) resulting from the Ramsey-type interference of the partial photoelectron wave packets created by each pulse. The slope of the spiral arms encodes the time delay between the partial wave packets with interferometric precision. We study the ionization time delay in the $1+2$ resonance-enhanced multiphoton ionization of potassium atoms using femtosecond CRCP white-light supercontinuum pulses. Pairwise interference of the partial wave packets with a reference wave packet gives rise to vortices of different rotational symmetry, which are superimposed to form the total PMD. The PMD is reconstructed tomographically and decomposed into the vortices using three-dimensional Fourier analysis. From the energy-dependent spectral phases of the vortices, we retrieve a resonant ionization delay on the order of 1 fs, much shorter than the pulse duration. Our results demonstrate the power of photoelectron vortices for the accurate determination of photoionization time delays and open up new perspectives for photoelectron chronoscopy including the measurement of ionization delays on the attosecond timescale.

arXiv:2410.01601•Physical Review A•Dec 16, 2024•4 citations

Photoelectron momentum distributions of Ne and Xe dimers in counter-rotating circularly polarized laser fields

Zhi-Xian Lei, Qing-Yun Xu, Zhijie Yang +2 more

The strong-field ionization of dimers is investigated theoretically in counter-rotating circularly polarized laser fields. By numerically solving the two-dimensional (2D) time-dependent Schrödinger equation (TDSE) with the single-electron approximation (SEA) frame, we present the photoelectron momentum distributions (PMDs) and photoelectron angular distribution (PADs) of aligned Ne and Xe dimers. It is found that the PMDs and PADs strongly depend on the time delays by counter-rotating circularly polarized laser pulses. The results can be explained by the ultrafast photoionization model and the evolution of electron wave packets for Ne and Xe dimers. Besides, We make a comparison of PMDs between Ne atom and Ne dimer.

Chinese Physics B•Jan 24, 2022•4 citations

Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

Diego I. R. Boll, O A Fojón

Abstract We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.

Journal of Physics B Atomic Molecular and Optical Physics•Sep 14, 2017•6 citations
We present a study of the time delay in atomic photo-ionization by circularly polarized laser pulse. We considered initial electron states that are co- and counter-rotating with respect to the electric field. We found, that similarly to the photoelectron spectra, studied extensively in the literature, the time delays are markedly different for these two orientations, depending sensitively on the field strengths and pulse durations.
We study time delay in atomic photoionization by circularly polarized light. By considering the Li atom in an excited 2p2p2p state, we demonstrate a strong time-delay asymmetry between the photoemission of the target electrons that are co- and counter-rotating with the electromagnetic field in the polarization plane. In addition, we observe the time-delay sensitivity to the polar angle of the photoelectron emission in the polarization plane. This modulation depends on the shape and duration of the electromagnetic pulse.
We investigate few-photon ionization of lithium atoms prepared in the polarized $2p\phantom{\rule{0.16em}{0ex}}({m}_{\ensuremath{\ell}}=+1)$ state when subjected to femtosecond light pulses with left- or right-handed circular polarization at wavelengths between 665 and 920 nm. We consider whether ionization proceeds more favorably for the electric field co- or counter-rotating with the initial electronic current density. Strong asymmetries are found and quantitatively analyzed in terms of ``circular dichroism'' (CD). While the intensity dependence of the measured CD values is rather weak throughout the investigated regime, a very strong sensitivity on the center wavelength of the incoming radiation is observed. While the co-rotating situation overall prevails, the counter-rotating geometry is strongly favored around 800 nm due to the $2p\text{\ensuremath{-}}3s$ resonant transition, which can only be driven by counter-rotating fields. The observed features provide insights into the helicity dependence of light-atom interactions, and on the possible control of electron emission in atomic few-photon ionization by polarization-selective resonance enhancement.
We study relativistic effects in the time delay of atomic photoionization using an example of the Xe atom subjected to a circularly polarized electromagnetic pulse. We find that while relativistic effects play only a fairly small role for both the ionization probabilities and the time delay of the corotating electron with the same sign of the angular momentum projection as the circularly polarized light, these effects produce substantial change in the time delay for a counter-rotating electron with the opposite sign of the angular momentum projection.
We study time delays in atomic multiphoton ionization (MPI) using the phase-sensitive detection of photoelectron vortices. Photoelectron vortices are created by MPI with counterrotating circularly polarized (CRCP) ultrashort double-pulse sequences. The vortices are characterized by a spiral-shaped photoelectron momentum distribution (PMD) resulting from the Ramsey-type interference of the partial photoelectron wave packets created by each pulse. The slope of the spiral arms encodes the time delay between the partial wave packets with interferometric precision. We study the ionization time delay in the 1+21+21+2 resonance-enhanced multiphoton ionization of potassium atoms using femtosecond CRCP white-light supercontinuum pulses. Pairwise interference of the partial wave packets with a reference wave packet gives rise to vortices of different rotational symmetry, which are superimposed to form the total PMD. The PMD is reconstructed tomographically and decomposed into the vortices using three-dimensional Fourier analysis. From the energy-dependent spectral phases of the vortices, we retrieve a resonant ionization delay on the order of 1 fs, much shorter than the pulse duration. Our results demonstrate the power of photoelectron vortices for the accurate determination of photoionization time delays and open up new perspectives for photoelectron chronoscopy including the measurement of ionization delays on the attosecond timescale.
The strong-field ionization of dimers is investigated theoretically in counter-rotating circularly polarized laser fields. By numerically solving the two-dimensional (2D) time-dependent Schrödinger equation (TDSE) with the single-electron approximation (SEA) frame, we present the photoelectron momentum distributions (PMDs) and photoelectron angular distribution (PADs) of aligned Ne and Xe dimers. It is found that the PMDs and PADs strongly depend on the time delays by counter-rotating circularly polarized laser pulses. The results can be explained by the ultrafast photoionization model and the evolution of electron wave packets for Ne and Xe dimers. Besides, We make a comparison of PMDs between Ne atom and Ne dimer.
Abstract We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.