Relativistic calculations of angle-dependent photoemission time delay

Kheifets, Anatoli; Mandal, Ankur; Deshmukh, P. C.; Dolmatov, V K; Keating, David; Manson, Steven T.

doi:10.1103/physreva.94.013423

Cited by 32 publications

(39 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C parameter is converted to the atomic time delay τ a by (8) and analyzed as a function of the photoelectron direction relative to the polarization axis. The angular dependence of τ a is compared with the analogous dependence of the Wigner time delay τ W [21]. The time delay difference τ a − τ W in the zero angle direction is compared with the hydrogenic CC correction τ CC [22].…”

Section: A Solution Of Tdsementioning

confidence: 99%

Simulation of angular-resolved RABBITT measurements in noble-gas atoms

2018

View full text Add to dashboard Cite

We simulate angular resolved RABBITT (Reconstruction of Attosecond Beating By Interference of Two-photon Transitions) measurements on valence shells of noble gas atoms (Ne, Ar, Kr, and Xe). Our non-perturbative numerical simulation is based on solution of the time-dependent Schrödinger equation for a target atom driven by an ionizing XUV and dressing IR fields. From these simulations we extract the angular dependent magnitude and phase of the RABBITT oscillations and deduce the corresponding angular anisotropy β parameter and Wigner time delay τW for the single XUV photon absorption which initiates the RABBITT process. Said β and τW parameters are compared with calculations in the random phase approximation with exchange (RPAE) which includes inter-shell correlation. This comparison is used to test various effective potentials employed in the one-electron TDSE. In lighter atoms (Ne and Ar), several effective potentials are found to provide accurate simulation of RABBITT measurements for a wide range of photon energies up to 100 eV above the valence shell threshold. In heavier atoms (Kr and Xe), the onset of strong correlation with the d-shell restricts the validity of the single active electron approximation to several tens of eV above the valence shell threshold.

show abstract

Section: A Solution Of Tdsementioning

confidence: 99%

Simulation of angular-resolved RABBITT measurements in noble-gas atoms

2018

View full text Add to dashboard Cite

show abstract

“…As shown in earlier work [21,22], the interplay between two different angular components may give rise to an anisotropic time delay τ W (also known as Wigner time delay [23]) of the photoelectron wave packet, which is generated by the absorption of one XUV photon. The relativistic case involves a more complex analysis of several spin-orbit split channels [24]. So far, the angular dependence of group delays was exclusively studied theoretically, and in the context of the ionization from a nonsymmetric orbital [21,25].…”

Section: Introductionmentioning

confidence: 99%

Angular dependence of photoemission time delay in helium

et al. 2016

View full text Add to dashboard Cite

Time delays of electrons emitted from an isotropic initial state with the absorption of a single photon and leaving behind an isotropic ion are angle independent. Using an interferometric method involving XUV attosecond pulse trains and an IR-probe field in combination with a detection scheme, which allows for full three-dimensional momentum resolution, we show that measured time delays between electrons liberated from the 1s 2 spherically symmetric ground state of helium depend on the emission direction of the electrons relative to the common linear polarization axis of the ionizing XUV light and the IR-probing field. Such time delay anisotropy, for which we measure values as large as 60 as, is caused by the interplay between final quantum states with different symmetry and arises naturally whenever the photoionization process involves the exchange of more than one photon. With the support of accurate theoretical models, the angular dependence of the time delay is attributed to small phase differences that are induced in the laser-driven continuum transitions to the final states. Since most measurement techniques tracing attosecond electron dynamics involve the exchange of at least two photons, this is a general and significant effect that must be taken into account in all measurements of time delays involving photoionization processes.

show abstract

“…The relativistic formalism of the angular dependent WTD is presented in [26]. Briefly, the electric dipole transition amplitude from an initial state a, (ljm), to the final statesā, (ljm), for linearly polarized photons in thê z direction is, to within an overall real multiplicative factor,…”

Section: Methodsmentioning

confidence: 99%

“…Here χ ν is a two-component spinor and C is a Clebsch-Gordan coefficient. We combine the reduced electric dipole matrix element ā Q (1) 1 a defined in [26] with the phase factors and introduce…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Strong dependence of photoionization time delay on energy and angle in the neighborhood of Fano resonances

et al. 2019

Self Cite

View full text Add to dashboard Cite

We uncover dramatic variations of the Wigner photoemission time delay with energy and angle in the vicinity of a Fano resonance with the time delay taking opposite signs at different angles at the same energy as well as at the opposite sides of the resonance at the same angle. These variations are illustrated by choosing the Ne 2s → 3p autoionizing state as a case study. Moreover, we demonstrate the existence of strikingly significant changes in time delay due to relativistic effects despite Ne being a low-Z atom. This finding shows the possibility for utilizing time delay chronoscopy as a new route towards experimental probing of relativistic interactions and the phases of individual transition matrix elements upon atomic photoionization of low-Z atoms. Finally, we develop a practical parameterization to model and explain the angle and energy variation of the autoionizing resonance time delay in the non-relativistic limit.

show abstract

Relativistic calculations of angle-dependent photoemission time delay

Cited by 32 publications

References 24 publications

Simulation of angular-resolved RABBITT measurements in noble-gas atoms

Simulation of angular-resolved RABBITT measurements in noble-gas atoms

Angular dependence of photoemission time delay in helium

Strong dependence of photoionization time delay on energy and angle in the neighborhood of Fano resonances

Contact Info

Product

Resources

About