Attosecond chronoscopy - what happens during attosecod-scale delays?

[Jarek 31]

TL;DR Summary

Getting beyond idealization of atomic processes as being instant

While naive description of atomic processes idealizes that they are instant, a decade ago they have started observing attosecond-scale delays.
~1000 articles citing 2010 Science "Delay in photoemission" https://scholar.google.pl/scholar?cites=15193546925951882986&as_sdt=2005&sciodt=0,5&hl=en

E.g. 2020 "Probing molecular environment through photoemission delays" https://www.nature.com/articles/s41567-020-0887-8

Attosecond chronoscopy has revealed small but measurable delays in photoionization, characterized by the ejection of an electron on absorption of a single photon. Ionization-delay measurements in atomic targets provide a wealth of information about the timing of the photoelectric effect, resonances, electron correlations and transport.

So what happens during such tiny delays - what can we tell about such e.g. electron dynamics leading to creation of EM wave of single optical photon?

 

[Astronuc]

Summary:: Getting beyond idealization of atomic processes as being instant

So what happens during such tiny delays - what can we tell about such e.g. electron dynamics leading to creation of EM wave of single optical photon?

How far does a photon travel in an attosecond? Is the delay simply due to propagation to and from?

Since this is new to me, I was looking for information on "attosecond chronography" and could only find 'old' material. For example, in 2010, there was an announcement of the shortest time measured - 20 attoseconds. Has there been further developments?

https://phys.org/news/2010-06-photoemission-accuracy.html
https://cordis.europa.eu/article/id/32261-20-attoseconds-the-shortest-time-ever-recorded

And here I was concerned about femtoseconds.

 

[Jarek 31]

Shouldn't photon propagate as EM wave: ~0.3 nm per attosecond?

I added Google Scholar link with ~1000 papers citing the 2010 article, here are 118 since 2020 - also lots of experimental: https://scholar.google.pl/scholar?a...sciodt=0,5&cites=15193546925951882986&scipsc=

 

[Jarek 31]

Indeed measured 247 zeptoseconds to pass through hydrogen molecule: https://science.sciencemag.org/content/370/6514/339
https://www.livescience.com/zeptosecond-shortest-time-unit-measured.html
https://www.sciencenews.org/article/photon-journey-molecule-shortest-event-zeptosecond-physics

A few talks about them from AAMOS20: Advances in Atomic, Molecular, and Optical Sciences 2020