Physical Review A

Phase differences in the photoemission from krypton in the fine-structure-split ionization channels P3/22 and P1/22

M. Baggash, H. Rottke

Published Jul 27, 2015• 4 citations

Abstract

Using the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) technique, a nonzero phase difference is observed in the two-photon ionization transition of krypton atoms into the ionization channels $^{2}P_{1/2}$ and $^{2}P_{3/2}$ when an electron is removed from the $4p$ shell. The phase difference is studied for excitation energies ranging from $\ensuremath{\approx}18\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$ up to $\ensuremath{\approx}28\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$. The phase differences are found to depend on the relative directions of linear polarization of the photoionization laser pulses and the pulses inducing the subsequent continuum-continuum transition. The experimental results are compared to phase differences calculated on the basis of dipole matrix elements for photoionization and scattering phases known for krypton from earlier experiments. The results indicate that the RABBITT phase differences do not give an obvious direct access to time-delay differences in the primary photoionization step of the atom.

DOI: 10.1103/physreva.92.013424

Related papers

Circularly polarized RABBITT applied to a Rabi-cycling atom

Yijie Liao, Edvin Olofsson, Jan Marcus Dahlström +3 more

Physical Review AApr 3, 20245 citations

Extracting phase information on continuum-continuum couplings

Anne Harth, Nicolas Douguet, Klaus Bartschat +2 more

Physical Review AFeb 8, 201927 citations

Decomposition of the transition phase in multi-sideband schemes for reconstruction of attosecond beating by interference of two-photon transitions

Divya Bharti, David Atri-Schuller, Gavin Menning +6 more

arXiv:2011.02989Physical Review AFeb 26, 202139 citations

Reconstruction of attosecond beating by interference of two-photon transitions on the lithium atom with Rabi oscillations

Yijie Liao, Yueming Zhou, Liang-Wen Pi +5 more

Physical Review AJun 24, 202212 citations

Circularly polarized RABBIT applied to a Rabi-cycling atom

Yijie Liao, Edvin Olofsson, Jan Marcus Dahlström +3 more

arXiv:2312.12076Dec 19, 20230 citations

Multi-sideband interference structures by high-order photon-induced continuum-continuum transitions in helium

Divya Bharti, Hemkumar Srinivas, Farshad Shobeiry +7 more

arXiv:2309.10877Physical Review AFeb 12, 20249 citations

Physical Review A

Phase differences in the photoemission from krypton in the fine-structure-split ionization channels P3/22 and P1/22

M. Baggash, H. Rottke

Published Jul 27, 2015• 4 citations

Publisher

Abstract

^{2}P_{1/2}

and

^{2}P_{3/2}

when an electron is removed from the

4p

shell. The phase difference is studied for excitation energies ranging from

\ensuremath{\approx}18\phantom{\rule{0.28em}{0ex}}\mathrm{eV}

up to

\ensuremath{\approx}28\phantom{\rule{0.28em}{0ex}}\mathrm{eV}

. The phase differences are found to depend on the relative directions of linear polarization of the photoionization laser pulses and the pulses inducing the subsequent continuum-continuum transition. The experimental results are compared to phase differences calculated on the basis of dipole matrix elements for photoionization and scattering phases known for krypton from earlier experiments. The results indicate that the RABBITT phase differences do not give an obvious direct access to time-delay differences in the primary photoionization step of the atom.

DOI: 10.1103/physreva.92.013424

Related papers

Circularly polarized RABBITT applied to a Rabi-cycling atom

Yijie Liao, Edvin Olofsson, Jan Marcus Dahlström +3 more

We utilize the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) technique to study the phase of a Rabi-cycling atom using circularly polarized extreme ultraviolet and infrared fields, where the infrared field induces Rabi oscillations between the $2s$ and $2p$ states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBITT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angle-resolved RABBITT phases have different behaviors when the extreme ultraviolet and infrared fields have co- and counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.We utilize the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) technique to study the phase of a Rabi-cycling atom using circularly polarized extreme ultraviolet and infrared fields, where the infrared field induces Rabi oscillations between the $2s$ and $2p$ states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBITT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angle-resolved RABBITT phases have different behaviors when the extreme ultraviolet and infrared fields have co- and counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.

Physical Review AApr 3, 20245 citations

Extracting phase information on continuum-continuum couplings

Anne Harth, Nicolas Douguet, Klaus Bartschat +2 more

In measurements of relative phases in photoionization processes, the contribution of continuum-continuum (CC) couplings to the atomic (Wigner) phases, corresponding to attosecond time delays, is currently accounted for only by theoretical models. Here, we introduce a measurement scheme that is sensitive to phase differences of CC transitions after photoionization in the presence of an optical field. The method allows us to separate CC transitions from the ionization process and can help in testing existing theoretical models. It is based on a multicolor interferometer, similar to the RABBITT (reconstruction of attosecond beating by interference of two-photon transitions) method. The key idea involves the comparison of two measurements with different orders of CC transitions. The scheme is illustrated by an ab initio calculation on atomic hydrogen.In measurements of relative phases in photoionization processes, the contribution of continuum-continuum (CC) couplings to the atomic (Wigner) phases, corresponding to attosecond time delays, is currently accounted for only by theoretical models. Here, we introduce a measurement scheme that is sensitive to phase differences of CC transitions after photoionization in the presence of an optical field. The method allows us to separate CC transitions from the ionization process and can help in testing existing theoretical models. It is based on a multicolor interferometer, similar to the RABBITT (reconstruction of attosecond beating by interference of two-photon transitions) method. The key idea involves the comparison of two measurements with different orders of CC transitions. The scheme is illustrated by an ab initio calculation on atomic hydrogen.

Physical Review AFeb 8, 201927 citations

Decomposition of the transition phase in multi-sideband schemes for reconstruction of attosecond beating by interference of two-photon transitions

Divya Bharti, David Atri-Schuller, Gavin Menning +6 more

Reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) is a technique that can be used to determine the phases of atomic transition elements in photoionization processes. In the traditional RABBITT scheme, the so-called asymptotic approximation considers the measured phase as a sum of the Wigner phase linked to a single-photon ionization process and the continuum-continuum phase associated with further single-photon transitions in the continuum. In this paper, we extend the asymptotic approximation to multi-sideband RABBITT schemes. The predictions from this approximation are then compared with results obtained by an ab initio calculation based on solving the time-dependent Schr\"odinger equation for atomic hydrogen.Reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) is a technique that can be used to determine the phases of atomic transition elements in photoionization processes. In the traditional RABBITT scheme, the so-called asymptotic approximation considers the measured phase as a sum of the Wigner phase linked to a single-photon ionization process and the continuum-continuum phase associated with further single-photon transitions in the continuum. In this paper, we extend the asymptotic approximation to multi-sideband RABBITT schemes. The predictions from this approximation are then compared with results obtained by an ab initio calculation based on solving the time-dependent Schr\"odinger equation for atomic hydrogen.

arXiv:2011.02989Physical Review AFeb 26, 202139 citations

Reconstruction of attosecond beating by interference of two-photon transitions on the lithium atom with Rabi oscillations

Yijie Liao, Yueming Zhou, Liang-Wen Pi +5 more

We present numerical simulations of the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) on lithium by solving the three-dimensional time-dependent Schr\"odinger equation. In our scheme, the infrared (IR) field couples the $2s$ and $2p$ states of lithium and leads to the Rabi oscillations of populations between these two states. We analyzed the RABBITT phases of the two peaks in the Rabi-oscillation-induced Autler-Townes splittings. Our results show that the relative phase between these two peaks changes with the photoelectron energy and depends on the intensity of the IR field. Moreover, in the angle-resolved RABBITT measurement, the phases of the two peaks depend differently on the emission angle of photoelectrons. These behaviors are traced back to the different initial phases of the electron wave packets emitted from the dressed $2p$ states and the competition among different ionization channels.We present numerical simulations of the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) on lithium by solving the three-dimensional time-dependent Schr\"odinger equation. In our scheme, the infrared (IR) field couples the $2s$ and $2p$ states of lithium and leads to the Rabi oscillations of populations between these two states. We analyzed the RABBITT phases of the two peaks in the Rabi-oscillation-induced Autler-Townes splittings. Our results show that the relative phase between these two peaks changes with the photoelectron energy and depends on the intensity of the IR field. Moreover, in the angle-resolved RABBITT measurement, the phases of the two peaks depend differently on the emission angle of photoelectrons. These behaviors are traced back to the different initial phases of the electron wave packets emitted from the dressed $2p$ states and the competition among different ionization channels.

Physical Review AJun 24, 202212 citations

Circularly polarized RABBIT applied to a Rabi-cycling atom

Yijie Liao, Edvin Olofsson, Jan Marcus Dahlström +3 more

We utilize the reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) technique to study the phase of a Rabi-cycling atom using circularly polarized extreme ultraviolet and infrared (IR) fields, where the IR field induces Rabi oscillations between the 2s and 2p states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBIT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angle-resolved RABBIT phases have different behaviors when the XUV and IR fields have co- and counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.We utilize the reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) technique to study the phase of a Rabi-cycling atom using circularly polarized extreme ultraviolet and infrared (IR) fields, where the IR field induces Rabi oscillations between the 2s and 2p states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBIT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angle-resolved RABBIT phases have different behaviors when the XUV and IR fields have co- and counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.

arXiv:2312.12076Dec 19, 20230 citations

Multi-sideband interference structures by high-order photon-induced continuum-continuum transitions in helium

Divya Bharti, Hemkumar Srinivas, Farshad Shobeiry +7 more

Following up on a previous paper on two-color photoionization of Ar(3p) [D. Bharti , ], we present measurements and calculations for a modified three-sideband (3-SB) version of the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) configuration applied to He(1s) . The 3-SB RABBITT approach allows us to explore interference effects between pathways involving different orders of transitions within the continuum. The relative differences in the retrieved oscillation phases of the three sidebands provide insights into the continuum-continuum transitions. The ground state of helium has zero orbital angular momentum, which simplifies the analysis of oscillation phases and their angle dependence within the three sidebands. We find qualitative agreement between our experimental results and the theoretical predictions for many cases but also observe some significant quantitative discrepancies. Published by the American Physical Society 2024Following up on a previous paper on two-color photoionization of Ar(3p) [D. Bharti , ], we present measurements and calculations for a modified three-sideband (3-SB) version of the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) configuration applied to He(1s) . The 3-SB RABBITT approach allows us to explore interference effects between pathways involving different orders of transitions within the continuum. The relative differences in the retrieved oscillation phases of the three sidebands provide insights into the continuum-continuum transitions. The ground state of helium has zero orbital angular momentum, which simplifies the analysis of oscillation phases and their angle dependence within the three sidebands. We find qualitative agreement between our experimental results and the theoretical predictions for many cases but also observe some significant quantitative discrepancies. Published by the American Physical Society 2024

arXiv:2309.10877Physical Review AFeb 12, 20249 citations

^{2}P_{1/2}

and

^{2}P_{3/2}

when an electron is removed from the

4p

shell. The phase difference is studied for excitation energies ranging from

\ensuremath{\approx}18\phantom{\rule{0.28em}{0ex}}\mathrm{eV}

up to

\ensuremath{\approx}28\phantom{\rule{0.28em}{0ex}}\mathrm{eV}

2s

and

2p

states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBITT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angle-resolved RABBITT phases have different behaviors when the extreme ultraviolet and infrared fields have co- and counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.

2s

and

2p

states of lithium and leads to the Rabi oscillations of populations between these two states. We analyzed the RABBITT phases of the two peaks in the Rabi-oscillation-induced Autler-Townes splittings. Our results show that the relative phase between these two peaks changes with the photoelectron energy and depends on the intensity of the IR field. Moreover, in the angle-resolved RABBITT measurement, the phases of the two peaks depend differently on the emission angle of photoelectrons. These behaviors are traced back to the different initial phases of the electron wave packets emitted from the dressed

2p

states and the competition among different ionization channels.