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

Canadian Journal of Physics

Measurability of Wigner time delay in a photoionization experiment

Pranawa C. Deshmukh, Sourav Banerjee, Steven Trent Manson

Published Mar 1, 2024• 2 citations
Publisher

Abstract

We visit significant historical steps in quantum collision physics that make photoionization time delay measurable, especially considering the time-reversal symmetry in related processes. The works of A. Ravi P. Rau and Ugo Fano inspire key ideas presented in this article.
DOI
10.1139/cjp-2023-0226

Related papers

Attosecond delays in photoionization: timeandquantum mechanics

A. Maquet, Jérémie Caillat, Richard Taïeb

This article addresses topics regarding time measurements performed on quantum systems. The motivation is linked to the advent of 'attophysics' which makes feasible to follow the motion of electrons in atoms and molecules, with time resolution at the attosecond (1 as = 10 −18 s) level, i.e. at the natural scale for electronic processes in these systems. In this context, attosecond 'time-delays' have been recently measured in experiments on photoionization and the question arises if such advances could cast a new light on the still active discussion on the status of the time variable in quantum mechanics. One issue still debatable is how to decide whether one can define a quantum time operator with eigenvalues associated to measurable 'time-delays', or time is a parameter, as it is implicit in the Newtonian classical mechanics. One objective of this paper is to investigate if the recent attophysics-based measurements could shed light on this parameter-operator conundrum. To this end, we present here the main features of the theory background, followed by an analysis of the experimental schemes that have been used to evidence attosecond 'time-delays' in photoionization. Our conclusion is that these results reinforce the view that time is a parameter which cannot be defined without reference to classical mechanics.

Journal of Physics B Atomic Molecular and Optical Physics•Oct 8, 2014•83 citations

Comment on ‘Time delays in molecular photoionization’

Denitsa Baykusheva, Hans Jakob Wörner

Abstract In a recent article by Hockett et al (2016 J. Phys. B: At. Mol. Opt. Phys. 49 095602), time delays arising in the context of molecular single-photon ionization are investigated from a theoretical point of view. We argue that one of the central equations given in this article is incorrect and present a reformulation that is consistent with the established treatment of angle-dependent scattering delays (Eisenbud 1948 PhD Thesis Princeton University; Wigner 1955 Phys. Rev. 98 145–7; Smith 1960 Phys. Rev. 118 349–6; Nussenzveig 1972 Phys. Rev. D 6 1534–42).

arXiv:1611.09352•Journal of Physics B Atomic Molecular and Optical Physics•Mar 15, 2017•6 citations

Time-reversal symmetry in optics*

Gerd Leuchs, M Sondermann

The utilization of time-reversal symmetry in designing and implementing (quantum) optical experiments has become more and more frequent over the last few years. We review the basic idea underlying time-reversal methods, illustrate it with several examples and discuss a number of implications.

arXiv:1205.1374•Physica Scripta•Apr 20, 2012•30 citations

Time-reversal symmetry in optics

Gerd Leuchs, Sondermann, M.

The utilization of time-reversal symmetry in designing and implementing (quantum) optical experiments has become more and more frequent over the last few years. We review the basic idea underlying time-reversal methods, illustrate it with several examples and discuss a number of implications.

•Jan 1, 2012•21 citations

Occurrences, observations and measurements in quantum mechanics

Stig Stenholm

This paper considers the recent description of quantum time evolution in terms of a sequence of discrete quantum jumps. The historical development of continuous time evolution versus sudden jumps is reviewed. A time irreversible master equation is derived heuristically by considering random interruptions of the Schrodinger time development by external interventions characterized by a broad spectrum. The concrete examples we have in mind are atomic collisions and photon counting events. The formulation chosen allows a more general approach to the problem than conventional perturbative treatments. The conserved quantities are considered, and the effects of a dynamical superselection rule is discussed. It is pointed out, that these often break the time reversal symmetry and constitute a counting process which can be regarded as a measurement. Under certain conditions, the intervening process can be decomposed into simple jump processes that allow a simulation in terms of a quantum stochastic process. The significance of the results, their historical origins and the relations to contemporary investigations are all being discussed.

Physica Scripta•Jun 1, 1993•19 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.

Physical Review A•Feb 8, 2019•27 citations
This article addresses topics regarding time measurements performed on quantum systems. The motivation is linked to the advent of 'attophysics' which makes feasible to follow the motion of electrons in atoms and molecules, with time resolution at the attosecond (1 as = 10 −18 s) level, i.e. at the natural scale for electronic processes in these systems. In this context, attosecond 'time-delays' have been recently measured in experiments on photoionization and the question arises if such advances could cast a new light on the still active discussion on the status of the time variable in quantum mechanics. One issue still debatable is how to decide whether one can define a quantum time operator with eigenvalues associated to measurable 'time-delays', or time is a parameter, as it is implicit in the Newtonian classical mechanics. One objective of this paper is to investigate if the recent attophysics-based measurements could shed light on this parameter-operator conundrum. To this end, we present here the main features of the theory background, followed by an analysis of the experimental schemes that have been used to evidence attosecond 'time-delays' in photoionization. Our conclusion is that these results reinforce the view that time is a parameter which cannot be defined without reference to classical mechanics.
Abstract In a recent article by Hockett et al (2016 J. Phys. B: At. Mol. Opt. Phys. 49 095602), time delays arising in the context of molecular single-photon ionization are investigated from a theoretical point of view. We argue that one of the central equations given in this article is incorrect and present a reformulation that is consistent with the established treatment of angle-dependent scattering delays (Eisenbud 1948 PhD Thesis Princeton University; Wigner 1955 Phys. Rev. 98 145–7; Smith 1960 Phys. Rev. 118 349–6; Nussenzveig 1972 Phys. Rev. D 6 1534–42).
This paper considers the recent description of quantum time evolution in terms of a sequence of discrete quantum jumps. The historical development of continuous time evolution versus sudden jumps is reviewed. A time irreversible master equation is derived heuristically by considering random interruptions of the Schrodinger time development by external interventions characterized by a broad spectrum. The concrete examples we have in mind are atomic collisions and photon counting events. The formulation chosen allows a more general approach to the problem than conventional perturbative treatments. The conserved quantities are considered, and the effects of a dynamical superselection rule is discussed. It is pointed out, that these often break the time reversal symmetry and constitute a counting process which can be regarded as a measurement. Under certain conditions, the intervening process can be decomposed into simple jump processes that allow a simulation in terms of a quantum stochastic process. The significance of the results, their historical origins and the relations to contemporary investigations are all being discussed.
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.